1971 census of Canada. Economic characteristics, labour force, occupations = Recensement du Canada 1971. Volume 3, partie 2, Caractéristiques économiques, population active, professions ; Bulletin 3.2-6
1971 census of Canada. Economic characteristics, labour force, occupations = Recensement du Canada 1971. Volume 3, partie 2, Caractéristiques économiques, population active, professions ; Bulletin 3.2-3
Commonwealth of Pennsylvania, Department of Labor and Industry, Office of Employment Security, affiliated with Employment and Training Administration, U.S. Department of Labor