- Anonymous (1983) In : 5th Workshop Report on Medicinal and Aromatic Plants, Solan, PP-I0.
- Anonymous (1998); In : 12th Workshop Report on Medicinal and Aromatic Plants, Hisar, pp-66.
Afield experiment for successive three years were conducted during 1995-96 to 199798
to evaluate the performance of periwinkle varieties. The varieties Selection-I and M-153
performed well under assured rainfall zone of Vidarbha region in respect of root and foliage
yield as well as alkaloid content and yield.