SACHAN, S. N. “Phenological Spectrum and Perennation of Powdery Mildew Fungi of Doon Valley-I-Erysiphe”. Indian Phytopathology, vol. 44, no. 1, Jan. 2002, pp. 121-3, https://epubs.icar.org.in/index.php/IPPJ/article/view/21837.