Não informado. (1923). Minnesota Studies in Plant Science. University of Minnesota.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Minnesota Studies in Plant Science. Minneapolis, Minn: University of Minnesota, 1923.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Minnesota Studies in Plant Science. University of Minnesota, 1923.
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