XII Population census. II Housing census
Census1981 are published in several volumes:
Provisional results. - Final results : Portugal, Aveiro, Beja, Braga, Bragança, Castelo Branco, Coimbra, Évora, Faro, Guarda, Leiria, Lisboa, Portalegre, Porto, Santarém, Setúbal, Viana do Castelo, Vila Real, Viseu, Açores, Madeira.
Also available a volume on history, methodologies and concepts