TY  - BOOK
AU  - Singh, Mahender Nath
TI  - Studies on the variable efficiency of aphid vectors in transmitting plant viruses and epidemiology of potato viruses Y and leafroll : thesis submitted for the degree of Philophy in Botany in the faculty of science Himachal Pradesh University Simla 1981
PY  - 1981///
CY  - Simla
PB  - Himachal Pradesh University
ER  -