Não informado. (1963). Explorations in Entrepreneurial History. Earlham College.
Chicago-referens (17:e uppl.)Não informado. Explorations in Entrepreneurial History. Richmond, Ind: Earlham College, 1963.
MLA-referens (8:e uppl.)Não informado. Explorations in Entrepreneurial History. Earlham College, 1963.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.