"§ 15.217 Operation in the band 160–190 kHz (47 CFR 15.217)". Part 15 — Radio frequency devices. ecfr.gov (Report). The Electronic Code of Federal Regulations. 47 CFR 15.217 (47 CFR 15.206). Retrieved 17 March 2024.[failed verification] Cited section 47 CFR 15.206 not present / removed: section id §15.205 skips to §15.207 .
Gale, Alan (G4TMV) (2011). World DGPS database for DXers(PDF) (Report). 4.6. Archived from the original(PDF) on 21 July 2011. Retrieved 14 January 2008 – via ndblist.info.{{cite report}}: CS1 maint: numeric names: authors list (link)
Gale, Alan (G4TMV) (2011). World DGPS database for DXers(PDF) (Report). 4.6. Archived from the original(PDF) on 21 July 2011. Retrieved 14 January 2008 – via ndblist.info.{{cite report}}: CS1 maint: numeric names: authors list (link)
wireless.org.uk
"QSO ZL / UA0 on 136 kHz". The World of LF. wireless.org.uk. Archived from the original on 29 September 2007. Retrieved 1 June 2006.