Archana R, Namasivayam A. Antistressor effect of Withania somnifera. Ethnopharmacol. 1999;64(1):91-3.
Mishra LC, Singh BB, Dagenais S. Scientific basis for the therapeutic use of Withania somnifera (ashwagandha): a review. Altern Med Rev. 2000 (4):334-46.