Amal F. Soliman, Zein M. Naeem, Ashraf T. Khalil, Kuniyoshi Shimizu, and Saleh H. El-Sharkawy. “Microbial Transformation of the Labdane Diterpene 13-Epi-Cupressic Acid”. World Journal of Pharmaceutical Sciences, vol. 6, no. 5, May 2018, pp. 61-69, https://wjpsonline.com/index.php/wjps/article/view/microbial-transformation-diterpene-epi-cupressic-acid.