Siang, Rafaella, et al. “FORMULATION AND EVALUATION OF TOPICAL PENTOXIFYLLINE-HYDROXYPROPYL METHYLCELLULOSE GELS FOR WOUND HEALING APPLICATION”. International Journal of Pharmacy and Pharmaceutical Sciences, vol. 6, no. 9, Sept. 2014, pp. 535-9, https://www.journals.innovareacademics.in/index.php/ijpps/article/view/1625.