engert, m. (1964). classification of industries in social countries. the institute of national planning.
Chicago-referens (17:e uppl.)engert, manfred. Classification of Industries in Social Countries. cairo: the institute of national planning, 1964.
MLA-referens (9:e uppl.)engert, manfred. Classification of Industries in Social Countries. the institute of national planning, 1964.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.