Vangnai, Somsak, Sawaeng Ruaysungnern, and Saipin Porntaveevatana. “Improved Growth Medium for Industrial Production of Rhizobium japonicum strain Soil-18”. Agriculture and Natural Resources 9, no. 2 (July 1, 1975): 119–125. accessed September 18, 2026. https://li01.tci-thaijo.org/index.php/anres/article/view/240718.