Shanmugam Manoharan, Mookkan Muneeswaran, and Nagarethinam Baskaran, “Chemopreventive efficacy of berberine in 7,12-dimethylbenz[a]anthracene (DMBA) induced skin carcinogenesis in Swiss albino mice”, Int. J. Res. Pharm. Sci., vol. 1, no. 4, pp. 521–529, Dec. 2010.