Joshi, Anil P., et al. “Association, Correlation and Regression Studies of Forest Floor of <I>Pinus roxburghii< I> Sarg. Of Garhwal Himalayas”. Indian Forester, vol. 112, no. 5, May 1986, pp. 387-91, doi:10.36808/if/1986/v112i5/9873.