Census 1961, England and Wales :
occupation, industry, socio-economic groups (laid before Parliament persuant [!] to Section 4(1), Census act, 1920)

APA Citation

Great Britain. General Register Office. (1965). Census 1961, England and Wales: occupation, industry, socio-economic groups (laid before Parliament persuant [!] to Section 4(1), Census act, 1920). London: H.M. Stationery Off..

MLA Citation

Great Britain. General Register Office. Census 1961, England And Wales: Occupation, Industry, Socio-economic Groups (laid Before Parliament Persuant [!] to Section 4(1), Census Act, 1920). London: H.M. Stationery Off., 1965.