Maneesawas, Soonthorn, and Somsak Vangnai. 1984. “Phosphorus Dissolution by Microbial Activities: 1.Dissolution of Rock Phosphate by Thiobacillus”. Agriculture and Natural Resources 18 (1). Bangkok, Thailand:20-23. https://li01.tci-thaijo.org/index.php/anres/article/view/240929.