Kumar, Munesh, et al. “Altitudinal Variation in Specific Gravity of <I>Pinus roxburghii< I> (Chir-Pine) in Garhwal Himalaya”. Indian Forester, vol. 144, no. 11, Jan. 2019, pp. 1122-4, doi:10.36808/if/2018/v144i11/141209.