V. A. Vasnev, G. D. Markova, B. A. Uvarov, W. Y. Voytekunas, and M. J. Abadie, “Catalysis of Trans-esterification Reactions in Model Ester Mixtures”, Eurasian Chem.-Technol. J., vol. 7, no. 2, pp. 79–84, Apr. 2005.