H. Jiang, S. Sun, C. Zhang, E. Yuan, Q. Wei, and Z. Zeng, “Antioxidative Activities of Natural Hydroxy-Bearing Cinnamaldehydes and Cinnamic Acids: A Comparative Study”, Trop. J. Pharm Res, vol. 12, no. 6, pp. 1017–1022, Jan. 2014.