Supamard Panichsakpatana. “Efficiency of Some Selected Organic Wastes as Nitrogen Source for Sweet Corn Grown on Kamphaeng Saen Soil”. Agriculture and Natural Resources, vol. 29, no. 3, Sept. 1995, pp. 358-70, https://li01.tci-thaijo.org/index.php/anres/article/view/241337.