R. P. Sharma, A. K. Das, and A. K. Raina, “Influence of Rocks, Soils and Physiography in the Distribution of <I>Swertia chirayita</I> and <I>Rubia cordifolia</I> in Metamorphic Terrain of Kaski District, Western Nepal”, Indian Forester, vol. 141, no. 1, pp. 18–25, Jan. 2015.