1. O. Polunin and A. Stainton, Flowers of the Himalayas, Oxford University Press, New Delhi, 1984, p. 353.
2. P. K. Gupta, Flora Nainitalensis: A Handbook of the Flowering Plants of Nainital, Navyug Publ., New Delhi, 1968, p. 300.
3. K. R. Kritikar and B. D. Basu, Indian Medicinal Plants, M/s Bishen Singh Mahendra Pal Singh, Periodical Experts, New Delhi, 1975, p. 2435.
4. N. L. Sagrera and J. P. Bartley, J. Sci. Food Agric., 6, 49 (1995).
5. J. A. Pino and J. Rosado, J. Essent. Oil Res., 12, 377 (2000).