Internal nutrient efficiencies of irrigated lowland rice in tropical and subtropical Asia - Witt, C.; Dobermann, A.; Abdulrachman, S.; Gines, H.C.; Guanghuo, Wang; Nagarajan, R.; Satawatananont, S.; Thuc Son, Tran; Sy Tan, Pham; Van Tiem, Le; Simbahan, G.C; Olk, D.C. (Elsevier, 1999)