Yoyrurob, S., P. Boonsai, and B. . Charnnok. “IMPROVEMENT OF DIGESTIBILITY OF METHANE PRODUCTION FROM OIL PALM FIBER BY HYDROTHERMAL PRETREATMENT”. Life Sciences and Environment Journal, vol. 21, no. 2, Sept. 2020, pp. 311-2, https://ph01.tci-thaijo.org/index.php/psru/article/view/240755.