Akaraphol Petchmala และ Artiwan Shotipruk. (2008) Biodiesel from purified palm oil and palm fatty acid in supercritical methanol with sulfated zirconia catalyst. Chulalongkorn University:ม.ป.ท.Akaraphol Petchmala และ Artiwan Shotipruk. 2008. Biodiesel from purified palm oil and palm fatty acid in supercritical methanol with sulfated zirconia catalyst. ม.ป.ท.:Chulalongkorn University;Akaraphol Petchmala และ Artiwan Shotipruk. Biodiesel from purified palm oil and palm fatty acid in supercritical methanol with sulfated zirconia catalyst. ม.ป.ท.:Chulalongkorn University, 2008. Print.