Não informado. (1929). Butler University botanical studies. Butler University, Department of Botany.
Chicago-Zitierstil (17. Ausg.)Não informado. Butler University Botanical Studies. Indianapolis, Ind: Butler University, Department of Botany, 1929.
MLA-Zitierstil (8. Ausg.)Não informado. Butler University Botanical Studies. Butler University, Department of Botany, 1929.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.