Mallika Tapanwong and Vittaya Punsuvon, “PRODUCTION OF ETHYL ESTER BIODIESEL FROM USED COOKING OIL WITH ETHANOL AND ITS QUICK GLYCEROL-BIODIESEL LAYER SEPARATION USING PURE GLYCEROL”, INTERNATIONAL JOURNAL OF GEOMATE, vol. 17, no. 61, pp. 109–114, Feb. 2019.