Sangtong, P. (1984) “Forms of Phosphate Accumulation in Soils as a Result of Heavy Fertilizer Application ”, Thai Agricultural Research Journal, 2(2), pp. 128–134. available at: https://li01.tci-thaijo.org/index.php/thaiagriculturalresearch/article/view/245671 (accessed: 1 October 2026).