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Tanner, R. L., , "Extremely low-frequency antenna". 1965.

Hansell, Clarence W., , "Communication system by pulses through the Earth".

Altshuler, , ELF vertical dipole antenna suspended from aircraft

Non-Ionizing Radiation, Part 1: Static dan Extremely Low-Frequency (ELF) Electric dan Magnetic Fields (2002)] oleh IARC. (Non-Ionizing Radiation)

Tomislav Stimac, "Definition of frequency bands (VLF, ELF... etc.)".  IK1QFK Home Page (vlf.it).

Extremely low frequency (ELF) fields (EHC 35, 1984)

"Radio waves below 22kHz: Nature's signals dan strange emission at very low frequency" - a site specialising in low-frequency signals .

Jacobsen, Trond, "ZEVS, the Russian 82 Hz ELF transmitter: An Extrem Low Frequency transmission-system, using the real longwaves" ALFLAB, Halden, Norway.

NASA live streaming ELF -> VLF Receiver