engert, m. (1964). classification of industries in social countries. the institute of national planning.
Citazione stile Chigago Style (17a edizione)engert, manfred. Classification of Industries in Social Countries. cairo: the institute of national planning, 1964.
Citatione MLA (9a ed.)engert, manfred. Classification of Industries in Social Countries. the institute of national planning, 1964.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.