Supamard Panichsakpatana. “Utilization of Effluent from Biogas Production as Nitrogen Source for Guinea Grass (Panicum maximum Jacq.) Grown on Kamphaeng Saen Soil”. Agriculture and Natural Resources, vol. 29, no. 2, June 1995, pp. 182-9, https://li01.tci-thaijo.org/index.php/anres/article/view/241314.