Rungruangsak, J., S. Sangkaphet, K. Buranaamnuay, P. Pongpeng, and P. Tummaruk. “Boar sperm production in a tropical environment”. The Thai Journal of Veterinary Medicine, vol. 51, no. 2, Feb. 2021, pp. 213-20, https://he01.tci-thaijo.org/index.php/tjvm/article/view/247796.