Sharma, Abhishek, and Naresh Chandra. “Isolation and Antioxidant Activity of Caffeic Acid from Roots of Bryophyllum Pinnatum (Lam.) Kurz”. Asian Journal of Chemistry, vol. 29, no. 2, Nov. 2016, pp. 267-70, doi:10.14233/ajchem.2017.20143.