Bhattarai, Shiva, Sunil Aryal, and Resham Thapa. “The Capacity of Lignin to Enhance the Phthorimaea Opercullela Granulovirus (PhopGV) Stability in Laboratory Condition”. International Journal of Applied Sciences and Biotechnology 3, no. 2 (June 25, 2015): 256-260. Accessed May 13, 2021. https://www.nepjol.info/index.php/IJASBT/article/view/12481.