Penny, E. M. (1932). The co-operative movement and the consumer. York: National Guild of Co-operators (NGC).
Chicago-referens (17:e uppl.)Penny, Edna M. The Co-operative Movement and the Consumer. York: National Guild of Co-operators (NGC), 1932.
MLA-referens (8:e uppl.)Penny, Edna M. The Co-operative Movement and the Consumer. York: National Guild of Co-operators (NGC), 1932.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.