Fixed service at frequences below about 30 Mhz : recommendations of the CCIR, 1990: (also and resolutions and opinions): volume III / International Telecommunication Union
Service fixe fonctionnant sur des fréquences inférieures á 30 Mhz environ : recommandations du CCIR, 1990: (ainsi que résolutions et voeux): volume III / Union Internationale des Télécommunications
Fixed service using radio-relay systems : recommendations of the CCIR, 1990: (also and resolutions and opinions): volume IX - part 1 / International Telecommunication Union
Propagation in non-ionized media : recommendations of the CCIR, 1990: (also and resolutions and opinions): volume V / International Telecommunication Union