Chantaraprateep, P., P. Prateep, P. Poomsuwan, and A. Kunavongkrit. “Artificial insemination in a commercial piggery”. Journal of Health Research, vol. 1, no. 2, May 2019, pp. 25-31, https://he01.tci-thaijo.org/index.php/jhealthres/article/view/191551.