Não informado. (1914). Contributions from the Department of Botany. Pennsylvania State College, Department of Botany.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Contributions from the Department of Botany. State College, Pa: Pennsylvania State College, Department of Botany, 1914.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Contributions from the Department of Botany. Pennsylvania State College, Department of Botany, 1914.
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