Não informado. (2008). State University of Iowa studies in natural history. State University of Iowa.
Chicago-Zitierstil (17. Ausg.)Não informado. State University of Iowa Studies in Natural History. Iowa City, Iowa: State University of Iowa, 2008.
MLA-Zitierstil (8. Ausg.)Não informado. State University of Iowa Studies in Natural History. State University of Iowa, 2008.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.