Não informado. (1919). University of Iowa Studies in Natural History. University of Iowa.
Chicagoスタイル(17版)引用形式Não informado. University of Iowa Studies in Natural History. Iowa City, Iowa: University of Iowa, 1919.
MLA(8版)引用形式Não informado. University of Iowa Studies in Natural History. University of Iowa, 1919.
警告: この引用は必ずしも正確ではありません.