Sittiboon Siripornakarachai และ Thawan Sucharitakul. (2008) Modification and Tuning of Multi-valve Diesel Bus Engine to Run On Biogas for Electricity Production. <i>International Journal of Renewable Energy</i>, <i>Vol. 3</i>(No.2), pp 1-13.Sittiboon Siripornakarachai และ Thawan Sucharitakul. "Modification and Tuning of Multi-valve Diesel Bus Engine to Run On Biogas for Electricity Production". International Journal of Renewable Energy Vol. 3 (2008):pp 1-13.Sittiboon Siripornakarachai และ Thawan Sucharitakul. Modification and Tuning of Multi-valve Diesel Bus Engine to Run On Biogas for Electricity Production. School of Renewable Energy Technology:ม.ป.ท. 2008.