Não informado. Polled Hereford World. American Polled Hereford Association.
Chicago-referens (17:e uppl.)Não informado. Polled Hereford World. Kansas City, Kan: American Polled Hereford Association.
MLA-referens (8:e uppl.)Não informado. Polled Hereford World. American Polled Hereford Association.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.