Fixed service at frequences below about 30 Mhz : reports of the CCIR, 1990: (also decisions): annex to volume III / International Telecommunication Union
Fixed-satellite service : reports of the CCIR, 1990: (also decisions): annex to volume IV - part 1 / International Telecommunication Union
Propagation in non-ionized media : reports of the CCIR, 1990: (also decisions): annex to volume V / International Telecommunication Union
Propagation in ionized media : reports of the CCIR, 1990: (also decisions): annex to volume VI / International Telecommunication Union