Não informado. (1960). Oklahoma current farm economics. Oklahoma Agricultural Experiment Station.
Chicago-referens (17:e uppl.)Não informado. Oklahoma Current Farm Economics. Stillwater, Okla: Oklahoma Agricultural Experiment Station, 1960.
MLA-referens (8:e uppl.)Não informado. Oklahoma Current Farm Economics. Oklahoma Agricultural Experiment Station, 1960.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.