Sakorn Phongpan และ Jenvith Sookthongsa. (2002) Effect of Urea Management on N Use Efficiency of Lowland Transplanted Rice. <i>Thai Agricultural Research Journal</i>, <i>20</i>(3), 250-266.Sakorn Phongpan และ Jenvith Sookthongsa. "Effect of Urea Management on N Use Efficiency of Lowland Transplanted Rice". Thai Agricultural Research Journal 20 (2002):250-266.Sakorn Phongpan และ Jenvith Sookthongsa. Effect of Urea Management on N Use Efficiency of Lowland Transplanted Rice. Department of Agriculture:ม.ป.ท. 2002.