Phongpan, Sakorn, and Janvith Sookthongsa. “Effect of Urea Management on N Use Efficiency of Lowland Transplanted Rice”. Thai Agricultural Research Journal 20, no. 3 (December 2, 2002): 250–266. accessed September 30, 2026. https://li01.tci-thaijo.org/index.php/thaiagriculturalresearch/article/view/219374.