Yearbook of statistics : telecommunications services: chronological time series 1989-1998 / International Telecommunication Union
Yearbook of statistics : telecommunications services: chronological time series 1988-1997 / International Telecommunication Union
Annuaire statistique des télécommunications du secteur public : (séries chronologiques 1980-1989) / Union Internationale des Télécommunications
Yearbook of statistics : telecommunication services: chronological time series 1986-1995 / International Telecommunication Union