Tikhonov, O. I., S. G. Bobro, and BlazheyevskiyМ. Y. “Quantitative Determination of the Content of Phenolic Compounds in a Gel With the Propolis Phenolic Hydrophobic Drug and Azelaic Acid”. Farmatsevtychnyi Zhurnal, no. 1, Sept. 2018, pp. 45-48, https://pharmj.org.ua/index.php/journal/article/view/149.