Sharma, V., and R. Kamal Sharma. “Pine Needle Energy Potential in Conifer Forest of Western Himalayan: DOI: 10.32526/Ennrj.18.1.2020.06”. Environment and Natural Resources Journal, vol. 18, no. 1, Sept. 2019, pp. 55-65, https://ph02.tci-thaijo.org/index.php/ennrj/article/view/217725.