Verma, V. P. S., and S. P. Pant. “Performance of Slash Pine (<I>Pinus elliottii< I> Engelm.) Vis-a-Vis Chirpine (<I>Pinus roxburghii< I> Sargent) in Respect of Oleoresin Yield at Dehra Dun”. Indian Forester, vol. 104, no. 11, Nov. 1978, pp. 768-71, doi:10.36808/if/1978/v104i11/11586.