Very low frequency (English Wikipedia)

Mardina Abdullah; et al. (2013) [2012]. Development of UKM-SID teaching module for space science education. 6th International Forum on Engineering Education (IFEE 2012). Procedia - Social and Behavioral Sciences. Vol. 102. pp. 80–85. doi:10.1016/j.sbspro.2013.10.716.
Fidani, Cristiano (8 December 2011). "The Central Italy Electromagnetic Network and the 2009 L'Aquila earthquake: Observed electric activity". Geosciences. 1 (1) (published 2012): 3–25. Bibcode:2011Geosc...1....3F. doi:10.3390/geosciences1010003. ISSN 2076-3263. Retrieved 14 January 2021.

elte.hu (Global: 5,814^th place; English: 7,639^th place)

plasmon.elte.hu

"AWDANet". plasmon.elte.hu.

geonics.com (Global: low place; English: low place)

"Geonics Limited - VLF Receivers". Retrieved 13 June 2014.

globalsecurity.org (Global: 443^rd place; English: 435^th place)

"Cutler". GlobalSecurity. Military Facilities.

harvard.edu (Global: 18^th place; English: 17^th place)

ui.adsabs.harvard.edu

Fidani, Cristiano (8 December 2011). "The Central Italy Electromagnetic Network and the 2009 L'Aquila earthquake: Observed electric activity". Geosciences. 1 (1) (published 2012): 3–25. Bibcode:2011Geosc...1....3F. doi:10.3390/geosciences1010003. ISSN 2076-3263. Retrieved 14 January 2021.

itu.int (Global: 986^th place; English: 803^rd place)

Final Acts WRC-15 (PDF). World Radiocommunication Conference. Geneva, Switzerland: International Telecommunications Union. 2015. p. 4. Retrieved 2025-01-12.

mdpi.com (Global: 2,912^th place; English: 6,319^th place)

Fidani, Cristiano (8 December 2011). "The Central Italy Electromagnetic Network and the 2009 L'Aquila earthquake: Observed electric activity". Geosciences. 1 (1) (published 2012): 3–25. Bibcode:2011Geosc...1....3F. doi:10.3390/geosciences1010003. ISSN 2076-3263. Retrieved 14 January 2021.

nasa.gov (Global: 75^th place; English: 83^rd place)

Susannah Darling (17 May 2017). "NASA's Van Allen Probes Spot Man-Made Barrier Shrouding Earth". NASA. Retrieved 11 June 2024.

navy-radio.com (Global: low place; English: low place)

Naval Shore Electronics Criteria - VLF, LF, and MF communications systems (PDF). Naval Electronics Systems Command. Washington, DC: U.S. Navy. August 1972. Manual NAVELEX 0101-113.

random-abstract.com (Global: low place; English: low place)

"Shortwave HF VHF UHF utilities monitoring". Random Abstract. 23 March 2025.

seklad69associates.com (Global: low place; English: low place)

Johnson, Richard C., ed. (1993). Antenna Engineering Handbook (PDF) (3rd ed.). McGraw-Hill. ISBN 007032381X.

smh.com.au (Global: 132^nd place; English: 96^th place)

"Naval base link to jet plunge". The Sydney Morning Herald. Sydney, AU. 14 November 2008. Retrieved 14 November 2008.

vlf.it (Global: low place; English: low place)

"20–25kHz". vlf.it.^{[full citation needed]}
"WA3248". ludb.clui.org. Archived from the original on 2011-09-27. Retrieved 2009-07-13.^{[full citation needed]}

web.archive.org (Global: 1^st place; English: 1^st place)

"20–25kHz". vlf.it.^{[full citation needed]}
"WA3248". ludb.clui.org. Archived from the original on 2011-09-27. Retrieved 2009-07-13.^{[full citation needed]}

worldcat.org (Global: 5^th place; English: 5^th place)

search.worldcat.org

Fidani, Cristiano (8 December 2011). "The Central Italy Electromagnetic Network and the 2009 L'Aquila earthquake: Observed electric activity". Geosciences. 1 (1) (published 2012): 3–25. Bibcode:2011Geosc...1....3F. doi:10.3390/geosciences1010003. ISSN 2076-3263. Retrieved 14 January 2021.

Very low frequency (English Wikipedia)

abelian.org (Global: low place; English: low place)

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cept.org (Global: low place; English: low place)

clui.org (Global: low place; English: low place)

ludb.clui.org

doi.org (Global: 2nd place; English: 2nd place)

elte.hu (Global: 5,814th place; English: 7,639th place)

plasmon.elte.hu

geonics.com (Global: low place; English: low place)

globalsecurity.org (Global: 443rd place; English: 435th place)

harvard.edu (Global: 18th place; English: 17th place)

ui.adsabs.harvard.edu

itu.int (Global: 986th place; English: 803rd place)

mdpi.com (Global: 2,912th place; English: 6,319th place)

nasa.gov (Global: 75th place; English: 83rd place)

navy-radio.com (Global: low place; English: low place)

random-abstract.com (Global: low place; English: low place)

seklad69associates.com (Global: low place; English: low place)

smh.com.au (Global: 132nd place; English: 96th place)

vlf.it (Global: low place; English: low place)

web.archive.org (Global: 1st place; English: 1st place)

worldcat.org (Global: 5th place; English: 5th place)

search.worldcat.org

archive.org (Global: 6^th place; English: 6^th place)

books.google.com (Global: 3^rd place; English: 3^rd place)

doi.org (Global: 2^nd place; English: 2^nd place)

elte.hu (Global: 5,814^th place; English: 7,639^th place)

globalsecurity.org (Global: 443^rd place; English: 435^th place)

harvard.edu (Global: 18^th place; English: 17^th place)

itu.int (Global: 986^th place; English: 803^rd place)

mdpi.com (Global: 2,912^th place; English: 6,319^th place)

nasa.gov (Global: 75^th place; English: 83^rd place)

smh.com.au (Global: 132^nd place; English: 96^th place)

web.archive.org (Global: 1^st place; English: 1^st place)

worldcat.org (Global: 5^th place; English: 5^th place)