Woronin, Michael Stepanovitch. Plasmodiophora brassicae : the cause of cabbage hernia / by Michael Stephanovitch Woronin. - Ithaca, N.Y. : American Phytopathological Society, 1934 - 32 p. : ill. - Phytopathological classics ; no. 4 . Subjects--Topical Terms: Clubroot.