Não informado. (1914). Contributions from the Department of Botany. Pennsylvania State College, Department of Botany.
Citação do estilo Chicago (17ª ed.)Não informado. Contributions from the Department of Botany. State College, Pa: Pennsylvania State College, Department of Botany, 1914.
Citação MLA (8ª ed.)Não informado. Contributions from the Department of Botany. Pennsylvania State College, Department of Botany, 1914.
Atenció: Aquestes cites poden no estar 100% correctes.