Space research and radioastronomy services : reports of the CCIR, 1990: (also opinions): annex to volume II / International Telecommunication Union
Fixed service at frequences below about 30 Mhz : reports of the CCIR, 1990: (also decisions): annex to volume III / International Telecommunication Union
Fixed service using radio-relay systems : reports of the CCIR, 1990: (also decisions): annex to volume IX - part 1 / International Telecommunication Union
Propagation in non-ionized media : reports of the CCIR, 1990: (also decisions): annex to volume V / International Telecommunication Union