Não informado. (1933). Contributions from the Botanical Laboratory and the Morris Arboretum of the University of Pennsylvania. University of Pennsylvania.
Chicagoスタイル(17版)引用形式Não informado. Contributions from the Botanical Laboratory and the Morris Arboretum of the University of Pennsylvania. Philadelphia, Pa: University of Pennsylvania, 1933.
MLA(8版)引用形式Não informado. Contributions from the Botanical Laboratory and the Morris Arboretum of the University of Pennsylvania. University of Pennsylvania, 1933.
警告: この引用は必ずしも正確ではありません.