Bhattarai, S., S. Aryal, and R. Thapa. “The Capacity of Lignin to Enhance the Phthorimaea Opercullela Granulovirus (PhopGV) Stability in Laboratory Condition”. International Journal of Applied Sciences and Biotechnology, Vol. 3, no. 2, June 2015, pp. 256-60, doi:10.3126/ijasbt.v3i2.12481.