Wijitphan, S., and P. Lowilai. “Effects of cattle manure and/or chemical fertilizer on yields and nutritive values of king Napier grass (Pennisetum purpureum cv. king grass) under irrigation (Thai)”. Asia-Pacific Journal of Science and Technology, vol. 15, no. 4, Apr. 2017, pp. 271-82, https://so01.tci-thaijo.org/index.php/APST/article/view/83162.