Siripaibool, Chantana. “Dinitrogen Fixation by Soybean under Zero and Conventional Tillage as Determined by Isotope Technology”. Thai Agricultural Research Journal 2, no. 2 (May 1, 1984): 120–127. accessed October 1, 2026. https://li01.tci-thaijo.org/index.php/thaiagriculturalresearch/article/view/245670.