Synopsis of the historical development of Schumann resonances

Radio Science

Volumn 42, Issue 2, 2007, Pages

  Besser, B P ^a  

^a Austrian Academy of Sciences ^*  (Austria)

Author keywords

[No Author keywords available]

Indexed keywords

ATMOSPHERIC ENVIRONMENT; EARTH-IONOSPHERE CAVITY; ELECTRICAL ACTIVITIES; ELECTROMAGNETIC OSCILLATIONS; EXPERIMENTAL EVIDENCE; EXTREMELY LOW FREQUENCIES; HISTORICAL DEVELOPMENT; NATURAL CAVITY; RESONANCE OSCILLATION; SCHUMANN RESONANCES; SCIENTIFIC COMMUNITY;

ELECTRIC FURNACES; ELECTROMAGNETIC WAVES; IONOSPHERE; IONOSPHERIC MEASUREMENT; RESONANCE;

ATMOSPHERIC ELECTRICITY;

EID: 41549093159     PISSN: 00486604     EISSN: None     Source Type: Journal    
DOI: 10.1029/2006RS003495     Document Type: Article

References (119)

1. Aarons, J. (1951), Low-frequency noise disturbance, Proc. Am. Acad. Arts Sci., 79, 266-279.
2. Abbas, M. (1968), Hydromagnetic wave propagation and excitation of Schumann resonances, Planet. Space Sci., 16, 831-844.
3. Al'pert, Y. L. (1963), Radio Wave Propagation and the Ionosphere, 364 pp., Consult. Bur., New York.
4. Alpert, Y. L. (2000), Making Waves: Stories From My Life, 260 pp., Yale Univ. Press, New Haven, Conn.
5. Antosiewicz, H. A. (1972), Bessel functions of fractional order, in Handbook of Mathematical Functions, edited by M. Abramowitz and I. A. Stegun, pp. 435-478, Dover, Mineola, N. Y.
6. Appleton, E. (1961), Sir Joseph Larmor and the ionosphere, Proc. R. Irish Acad., Ser. A, 61, 55-66.
7. Appleton, E. V., and M. A. F. Barnett (1925), On some direct evidence for downward atmospheric reflection of electric rays, Proc. R. Soc. London, Ser. A, 109, 621-641.
8. Balser, M., and C. A. Wagner (1960a), Measurements of the spectrum of radio noise from 50 to 100 cycles per second, J. Res. Natl. Bur. Stand. U. S., Sect. D, 64, 415-419.
9. Balser, M., and C. A. Wagner (1960b), Observations of Earthionosphere cavity resonances, Nature, 188, 638-641.
10. Barr, R., D. Llanwyn Jones, and C. J. Rodger (2000), ELF and VLF radio waves, J. Atmos. Sol. Terr. Phys., 62, 1689-1718.
11. Bateman, H. (1915), The Mathematical Analysis of Electrical and Optical Wave-Motion on the Basis of Maxwell's Equations, 159 pp., Cambridge Univ. Press, Cambridge, U. K.
12. Bering III, E. A.,, A. A. Few, and J. R. Benbrook (1998), The global electric circuit, Phys. Today, 51(10), 24-30.
13. Bioelectromagnetics Society Newsletter (2000), In memoriam Charles Polk, 156, Bioelectromagnetics Society Newsletter, 1-3.
14. Blackband, W. T. (Ed.) (1964), Propagation of Radio Waves at Frequencies Below 300 kc/s, 478 pp., Pergamon, Oxford, U. K.
15. Bliokh, P. V., A. P. Nickolaenko, and Y. F. Fillippov (1980), Schumann Resonances in the Earth-Ionosphere Cavity, IEE Electromagn. Wave Ser., vol. 9, 166 pp., Peter Peregrinus, London.
16. Booker, H. G. (1974), Fifty years of the ionosphere. The early years-Electromagnetic theory, J. Atmos. Terr. Phys., 36, 2113-2136.
17. Booker, H. G. (1975), Developments in the theory of radio propagation, 1900-1950, Radio Sci., 10(7), 665-668.
18. Borodina, S. V., Y. K. Kalinin, G. A. Mihaylova, and D. S. Fligel (1960), Obzor sovremennogo sostoyaniya issledovaniy rasprstraneniya sverhlinnih elektromagntnih voln (Review of the contemporary status of research on the propagation of ultra-long electromagnetic waves), Izv. Vyssh. Uchebn. Zaved. Radiofiz., 3(1), 5-32.
19. Breit, G., and M. A. Tuve (1926), A test of the existence of the conducting layer, Phys. Rev., 28, 554-573.
20. Bremmer, H. (1948), General remarks on the theory of wave propagation, in Atti del Congresso Internazionale per il Cinquantenario della Scoperta Marconiana della Radio, pp. 30-42, Dott. Giovanni Bardi, Rome.
21. Broc, J. (1950), Sur les caractéristiques des cavités résonnantes électromagnétiques constituées par deux sphères concentriques (On the characteristiques of the electromagnetic resonant cavity constituted by two concentric spheres), C. R. Hebd. Seances Acad. Sci., 230, 198-199.
22. Budden, K. G. (1951), The propagation of a radio-atmospheric, Philos. Mag., 42, 1-19.
23. Budden, K. G. (1952), The propagation of a radio atmospheric-II., Philos. Mag., 43, 1179-1200.
24. Budden, K. G. (1961), The Wave-Guide Mode Theory of Wave Propagation, 325 pp., Logos, London.
25. Burrows, C. R. (1948), Mechanisms of propagation, in Atti del Congresso Internazionale per il Cinquantenario della Scoperta Marconiana della Radio, pp. 43-51, Dott. Giovanni Bardi, Rome.
26. Burrows, M. L. (1978), ELF Communications Antennas, IEE Electromagn. Wave Ser., vol. 5, 245 pp., Peter Peregrinus, London.
27. Chapman, F. W., and D. L. Jones (1964), Observations of Earth-ionosphere cavity resonances and their interpretation in terms of a two-layer ionosphere model, J. Res. Natl. Bur. Stand. U. S., Sect. D, 68, 1177-1185.
28. Cole, R. K. (1965), The Schumann resonances, J. Res. Natl. Bur. Stand. U. S., Sect. D, 69, 1345-1349.
29. Eckart, G. (1975), Winfried Otto Schumann, Arch. Elektron. Uebertrag., 29, 52.
30. Fischer, E. P. (2006), Fremde Federn. Kolumne: Im Gegenteil (Adorn with borrowed plumes. Column: On the contrary), Welt, 27, 24 July. (Available online at http://www.welt.de/data/2006/07/24/970463.html.)
31. FitzGerald, G. F. (1893), On the period of vibration of electrical disturbances upon the Earth, in Rep. Meet. Br. Assoc. Adv. Sci., 63, 682.
32. FitzGerald, G. F. (1902), The Scientific Writings of the Late George Francis FitzGerald, edited by J. Larmor, 576 pp., Hodges, Figgis, Dublin.
33. Galejs, J. (1965), Schumann resonances, J. Res. Natl. Bur. Stand. U. S., Sect. D, 69, 1043-1055.
34. Galejs, J. (1972), Terrestrial Propagation of Long Electromagnetic Waves, 362 pp., Pergamon, Oxford, U. K.
35. Gendrin, R., and R. Stefant (1962a), Effet de l'explosion thermonucle ́aire à très haute altitude du 9 juillet 1962 sur la résonance de la cavité terre-ionosphère. Résultats expérimentaux (Effect of high altitude thermonuclear explosion on 9 July 1962 on the resonance of the Earth-ionosphere cavity. Experimental results), C. R. Hebd. Seances. Acad. Sci., 255, 2273-2275.
36. Gendrin, R., and R. Stefant (1962b), Effet de l'explosion thermonucléaire à très haute altitude du 9 juillet 1962 sur la résonance de la cavité terre-ionosphère. Interprétation (Effect of high altitude thermonuclear explosion on 9 July 1962 on the resonance of the Earth-ionosphere cavity. Interpretation), C. R. Hebd. Seances. Acad. Sci., 255, 2493-2495.
37. Ginzburg, V. L. (1961), Propagation of Electromagnetic Waves in Plasma, 822 pp., Gordon and Breach, New York.
38. Green, A. L. (1946), Early history of the ionosphere, Amalgamated Wireless Australasia Tech. Rev., 7(2), 177-228.
39. Hales, A. L. (1948), A possible mode of propagation of the 'slow' or tail component in atmospherics, Proc. R. Soc. London, Ser. A, 193, 60-71.
40. Heilbron, J. L. (1976), Thomson, Joseph John, in Dictionary of Scientific Biography, vol. 13, edited by C. C. Gillispie, pp. 362-372, Scribner, New York.
41. Holzer, R. E., and O. E. Deal (1956), Low audio-frequency electromagnetic signals of natural origin, Nature, 177, 536-537.
42. Jackson, J. D. (1998), Classical Electrodynamics, 3rd ed., 808 pp., John Wiley, Hoboken, N. J.
43. Jackson, J. D. (2003), FitzGerald's observation preceded Tesla's, Am. Phys. Soc. News, 17(7), 4.
44. Jones, D. L. (1964), The calculation of the Q factors and frequencies of Earth-ionosphere cavity resonances for a two-layer model, J. Geophys. Res., 69(19), 4037-4046.
45. Kazantsev, A. N. (1957), U. S. S. R research into radio wave propagation in the ionosphere, Radio Eng. Electron., Engl. Transl., 2(11), 62-83.
46. Killy, W. (Ed.) (1995), Arnold, Engelbert, in Deutsche Biographische Enzyklopad̈ie, vol. 1, p. 186, K. G. Saur, Munich, Germany.
47. Killy, W., and R. Vierhaus (Eds.) (1998), Schumann, Winfried (Otto), in Deutsche Biographische Enzyklopad̈ie, vol. 9, p. 208, K. G. Saur, Munich, Germany.
48. Knoll, M. (1968), Zum 80. Geburtstag von W. O. Schumann (To the 80th birthday of W. O. Schumann), Z. Angew. Phys., 25, 1.
49. Kon̈ig, F. M. (2005), Ein historischer Ruc̈kblick "in die Zukunft'' um die Schumann-Resonanz (A historical review ''into the future'' about the Schumann resonance), Wetter Boden Mensch, no. 2, 13-24.
50. Kon̈ig, H. (1959), Atmospherics geringster Frequenzen (Atmospherics of lowest frequencies), Z. Angew. Phys., 11, 264-274.
51. Kon̈ig, H. (1960), Ultra-low-frequency atmospherics, in IRE International Convention Record, vol. 8, part 1, pp. 128-133, Inst. of Electr. and Electron. Eng., New York.
52. Kon̈ig, H. L. (1975), Unsichtbare Umwelt. Der Mensch im Spielfeld elektromagnetischer Kräfte (The Invisible Environment. The Human Being Influenced by Electromagnetic Interactions), 203 pp., Herbert L. Koenig, Munich, Germany.
53. Krasnushkin, P. E. (1962a), K teorii zemnih atmosferikov (On the theory of terrestrial atmospherics), Dokl. Akad. Nauk SSSR, 144(2), 334-337.
54. Krasnushkin, P. E. (1962b), On the propagation of long and very long waves around the Earth, Nuovo Cimento Suppl. Ser. 10, 26(1), 50-112.
55. Lampa, A. (1903), Über die elektromagnetischen Schwingungen einer Kugel sowie ub̈er diejenigen einer Kugel, welche von einer konzentrischen dielektrischen Kugelschale umgeben ist (On the electromagnetic oscillations of a sphere as well as those of a sphere, which is surrounded by a concentric dielectric spherical shell), Sitzungsber. Math. Naturwiss. Kl. Kaiserliche Akad. Wiss. Wien, 112, part IIa, 37-66.
56. Larmor, J. (1929), Electric vibrations in condensing dielectric systems, in Mathematical and Physical Papers, vol. 1, pp. 356-378, Cambridge Univ. Press, Cambridge, U. K.
57. Liebermann, L. (1956a), Extremely low-frequency electromagnetic waves. I. Reception from lightning, J. Appl. Phys., 27(12), 1473-1476.
58. Liebermann, L. (1956b), Extremely low-frequency electromagnetic waves. II. Propagation properties, J. Appl. Phys., 27(12), 1477-1483.
59. Macdonald, H. M. (1902), Electric Waves, 200 pp., Cambridge Univ. Press, Cambridge, U. K.
60. Madden, T., and W. Thompson (1965), Low-frequency electromagnetic oscillations of the Earth-ionosphere cavity, Rev. Geophys., 3, 211-254.
61. Medicus, G. (1948), Zum 60. Geburtstag von Prof. Dr.-Ing. W. O. Schumann am 20. Mai 1948 (To the 60th birthday of W. O. Schumann), Z. Angew. Phys., 1, 105-106.
62. Menzel, D. H., and W. W. Salisbury (1948), Audio-frequency radio waves from the Sun, Nature, 161, 91.
63. Mie, G. (1908), Beitrag̈e zur Optik trub̈er Medien, speziell kolloidaler Metallos̈ungen (Contributions to the optics of turbid media, particularly of colloidal metal solutions), Ann. Phys., 25, 377-445.
64. Nature (1893), The period of vibration of disturbances of electrification of the Earth, Nature, 48, 526-529.
65. Nicholson, J. W. (1906), The symmetrical vibrations of conducting surfaces of revolution, Philos. Mag., 11, 703-721.
66. Nickolaenko, A. P., and M. Hayakawa (2002), Resonances in the Earth-Ionosphere cavity, 380 pp., Kluwer Acad., Doordrecht, Netherlands.
67. Noether, F. (1933), Bemerkungen ub̈er das Ausbreitungsgesetz für lange Wellen und die Wirkung der Heavisideschicht (Comments about the propagation law for long electrical waves and the effect of the Heaviside-layer), Elektr. Nachrichtentech., 10, 160-172.
68. Olver, F. W. J. (1972), Bessel functions of integer order, in Handbook of Mathematical Functions, edited by M. Abramowitz and I. A. Stegun, pp. 355-433, Dover, Mineola, N. Y.
69. Piloty, H. (1958), W. O. Schumann zum 70. Geburtstag (W. O. Schumann dedicated to his 70th birthday), Elektrotechn. Z., 79, 369-371.
70. Poeverlein, H. (1961), Resonance of the space between Earth and ionosphere, J. Res. Natl. Bur. Stand. U. S., Sect. D, 65, 465-473.
71. Poggendorff, J. C. (Ed.) (1904), Schumann, Ernst Otto, in J. C. Poggendorffs Biographisch-Literarisches Handwor̈terbuch zur Geschichte der Exacten Wissenschaften, vol. 4, part 2, pp. 1365-1366, Verl. Barth, Leipzig, Germany.
72. Poggendorff, J. C. (Ed.) (1940), Schumann, Winfried Otto, in J. C. Poggendorffs Biographisch-Literarisches Handwor̈terbuch, vol. 6, part 4, p. 2386, Verl. Chem., Berlin.
73. Poggendorff, J. C. (Ed.) (1956), Arnold, Engelbert, in J. C. Poggendorffs Biographisch-Literarisches Handwor̈terbuch zur Geschichte der Exacten Naturwissenschaften, vol. 7a, part 1, p. 57, Akademie, Berlin.
74. Poggendorff, J. C. (Ed.) (1961), Schumann, Winfried Otto, in J. C. Poggendorffs Biographisch-Literarisches Handwor̈terbuch zur Geschichte der Exacten Naturwissenschaften, vol. 7a, part 4, pp. 329-330, Akademie, Berlin.
75. Polk, C. (1982), Schumann resonances, in CRC Handbook of Atmospherics, vol. 1, edited by H. Volland, pp. 111-178, CRC Press, Boca Raton, Fla.
76. Polk, C. (2000), In memoriam of Professor Herbert Koenig, Bioelectromagn. Newsl., 156, 8, May/June.
77. Polk, C., and F. Fitchen (1962), Schumann resonances of the Earthionsophere cavity-Extremely low frequency reception at Kingston, R. I., J. Res. Natl. Bur. Stand. U. S., Sect. D, 66, 313-318.
78. Rakov, V. A., and M. A. Uman (2005), Lightning: Physics and Effects, 687 pp., Cambridge Univ. Press, Cambridge, U. K.
79. Ros̈ner, O. (1957), Die Ausbreitung elektromagnetischer TE-(H)-Wellen, erzeugt durch eine horizontale, stromdurchflossene Leiterschleife, in dem Hohlraum zwischen zwei konzentrischen Kugeln (Propagation of electromagnetic TE-(H)-waves, which are created by a horizontal, current carrying conducting loop, in the cavity between two concentric spheres), Z. Angew. Phys., 9, 448-453.
80. Rycroft, M. J. (1965), Resonances of the Earth-ionosphere cavity observed at Cambridge, England, J. Res. Natl. Bur. Stand. U. S., Sect. D, 69, 1071-1081.
81. Rydbeck, O. E. H. (1944), On the propagation of radio waves, in Trans. Chalmers Univ. Technol., no. 34, 1-169, Flanders Boktryckeri Aktiebolag, Goteborg, Sweden.
82. Rydbeck, O. E. H. (1948), On the forced electro-magnetic oscillations on spherical resonators, Philos. Mag., 39, 633-644.
83. Schelkunoff, S. A. (1943), Electromagnetic Waves, 530 pp., Van Nostrand Reinhold, Hoboken, N. J.
84. Schelkunoff, S. A. (1957), Sergei Alexander Schelkunoff, IRE Trans. Microwave Theory Tech., 5(3), 172.
85. Schlegel, K., and M. Ful̈lekrug (2002), 50 Jahre Schumann-Resonanzen. Weltweite Ortung von Blitzen (50 years of Schumann resonances. Worldwide location finding of lightning), Phys. Unserer Z., 33(6), 256-261.
86. Schumann, W. O. (1952a), Über die strahlungslosen Eigenschwingungen einer leitenden Kugel, die von einer Luftschicht und einer Ionosphar̈ enhülle umgeben ist (On the free eigen-oscillations of a conducting sphere, surrounded by an air film and an ionospheric shell), Z. Naturforsch. A, 7, 149-154.
87. Schumann, W. O. (1952b), Über die Dam̈pfung der elektromagnetischen Eigenschwingungen des Systems Erde-Luft-Ionosphar̈e (On the damping of the electromagnetic eigen-oscillations of the Earth-air-ionosphere system), Z. Naturforsch. A, 7, 250-252.
88. Schumann, W. O. (1952c), Über die Ausbreitung sehr langer elektrischer Wellen und der Blitzentladung um die Erde (On the propagation of very long electrical waves and the lightning discharge around the Earth), Z. Angew. Phys., 4, 474-480.
89. Schumann, W. O. (1952d), Über die Ausbreitung sehr langer elektrischer Wellen und das Wellenspektrum der Blitzentladung (On the propagation of very long electrical waves and the wave spectrum of a lightning discharge), Naturwissenschaften, 39, 475-476.
90. Schumann, W. O. (1952e), Über die Ausbreitung sehr langer elektrischer Wellen um die Erde und die Signale des Blitzes (On the propagation of very long electrical waves around the Earth and the signals of the lightning discharge), Nuovo Cimento, 9, 1116-1138.
91. Schumann, W. O. (1953), Über die Oberwellenfelder bei der Ausbreitung langer elektrischer Wellen um die Erde und die Signale des Blitzes (On the harmonic wave fields of the propagation of long electric waves round the Earth and the signals of a lightning stroke), Naturwissenschaften, 40, 504-505.
92. Schumann, W. O. (1954a), Über die Oberfelder bei der Ausbreitung langer, elektrischer Wellen im System Erde-Luft-Ionosphar̈e und 2 Anwendungen (horizontaler und senkrechter Dipol) (On the harmonic fields of the propagation of long electric waves in the Earth-air-ionosphere system and two applications (horizontal and vertical dipole)), Z. Angew. Phys., 6, 35-43.
93. Schumann, W. O. (1954b), Über die Strahlung langer Wellen des horizontalen Dipols in dem Lufthohlraum zwischen Erde und Ionosphar̈e, I., (On the radiation of long waves from a horizontal dipole in the cavity between Earth and the ionosphere, I.), Z. Angew. Phys., 6, 225-229.
94. Schumann, W. O. (1954c), Über die Strahlung langer Wellen des horizontalen Dipols in dem Lufthohlraum zwischen Erde und Ionosphar̈e, I., (On the radiation of long waves from a horizontal dipole in the cavity between Earth and the ionosphere, II.), Z. Angew. Phys., 6, 267-271.
95. Schumann, W. O. (1954d), Über die Ausbreitung langer elektrischer Wellen um die Erde und einige Anwendungen auf Senderinterferenzen und Blitzsignale (On the propagation of long electric waves around the Earth and some applications to transmitter interferences and lightning signals), Z. Angew. Phys., 6, 346-352.
96. Schumann, W. O. (1955), Der Einfluß des Erdmagnetfeldes auf die Ausbreitung elektrischer Lan̈gstwellen (The influence of the Earth's magnetic field on the propagation of long electrical waves), Z. Angew. Phys., 7, 284-290.
97. Schumann, W. O. (1957), Über elektrische Eigenschwingungen des Hohlraumes Erde-Luft-Ionosphar̈e, erregt durch Blitzentladungen (On electrical eigen-oscillations of the Earthair-ionosphere cavity, excited by lightning discharges), Z. Angew. Phys., 9, 373-378.
98. Schumann, W. O., and H. Kon̈ig (1954), Über die Beobachtung von ''atmospherics'' bei geringsten Frequenzen (On the observation of ''atmospherics'' at lowest frequencies), Naturwissenschaften, 41, 183-184.
99. Sentman, D. D. (1995), Schumann resonances, in Handbook of Atmospheric Electrodynamics, vol. 1, pp. 267-295, edited by H. Volland, CRC Press, Boca Raton, Fla.
100. Shmoys, J. (1956), Long-range propagation of low-frequency radio waves between the earth and the ionosphere, Proc. IRE, 44, 163-170.
101. Smith, E. K. (2000), James R. Wait-Remarkable scientist, IEEE Trans. Antennas Propag., 48(9), 1278-1286.
102. Stab̈lein, H.-G. (1955), Bemerkungen zur Ausbreitung langwelliger Blitzsignale um die Erde (Notes on the propagation of long wave lightning signals around the Earth), Z. Angew. Phys., 7, 290-291.
103. Stab̈lein, H.-G., and F. W. Heilbronner (1991), Winfried Otto Schumann, IEEE Trans. Electr. Insul., 26(3), 340-343.
104. Tesla, N. (1905), Art of transmitting electrical energy through the natural mediums, Patent 787.412, U. S. Patent and Trademark Off., Washington, D. C. (Available at http://freeinternetpress.com/mirrors/tesla-haarp/index.html.)
105. Thomson, J. J. (1893), Notes on Recent Researches in Electricity and Magnetism, Intended as a Sequel to Professor Clerk-Maxwell's Treatise on Electricity and Magnetism), 578 pp., Clarendon, Oxford, U. K.
106. Thomson, W. (1872), Atmospheric electricity, in Reprint of Papers on Electrostatics and Magnetism, edited by W. T. Kelvin, pp. 192-236, Macmillan, New York.
107. Vladimirov, N. P., and N. G. Kleimenova (1962), On the structure of the Earth's natural electromagnetic field in the frequency range of 0.5 - 100 cps, Bull. Acad. Sci. USSR Geophys. Ser., 6(10), 852-855.
108. Volland, H. (1968), Die Ausbreitung langer Wellen (Propagation of Long Waves), 232 pp., Vieweg, Braunschweig, Germany.
109. Wait, J. R. (1960), On the theory of the slow-tail portion of atmospheric waveforms, J. Geophys. Res., 65(7), 1939-1946.
110. Wait, J. R. (1962), Electromagnetic Waves in Stratified Media, 372 pp., Pergamon, Oxford, U. K. (Reprinted by IEEE Press, Piscataway, N. J., 1996)
111. Wait, J. R. (1974a), Historical background and introduction to the special issue on extremely low frequency (ELF) communication, IEEE Trans. Commun., 22(4), 353-354.
112. Wait, J. R. (1974b), Dedication to Janis Galejs, IEEE Trans. Commun., 22(4), 355.
113. Wait, J. R. (1977), Propagation of ELF electromagnetic waves and project Sanguine/Seafarer, IEEE J. Oceanic Eng., 2(2), 161-172.
114. Watson, G. N. (1918), The transmission of electric waves round the Earth, Proc. R. Soc., London, Ser. A, 95, 546-563.
115. Watson-Watt, R. A., J. F. Herd, and F. E. Lutkin (1937), On the nature of atmospherics-V, Proc. R. Soc. London, Ser. A, 162, 267-285.
116. Watt, A. D., R. D. Crogham, and J. R. Wait (1967), Propagation, in VLF Radio Engineering, Int. Ser. Monogr. Electromagn. Waves, vol. 14, edited by A. D. Watt, pp. 171-394, Pergamon, Oxford, U. K.
117. Weidner, J. (1955), Über eine Verfeinerung der Theorie der Ausbreitung langer elektrischer Wellen um die Erde (On a refinement of the theory of long electrical waves propagation around the Earth), Z. Angew. Phys., 7, 77-82.
118. Whittaker, E. T. (1935), Hector Munro Macdonald 1865-1935, Obituary Notices Fellows R. Soc. London, 1, 551-558.
119. Willis, H. F. (1948), Audio-frequency magnetic fluctuations, Nature, 161, 887-888.