Noppibool, Udomsak, Skorn Koonawootrittriron, Mauricio A. Elzo, and Thanathip Suwanasopee. 2016. “Factors Affecting Length of Productive Life and Lifetime Production Traits in a Commercial Swine Herd in Northern Thailand”. Agriculture and Natural Resources 50 (1). Bangkok, Thailand:71-74. https://li01.tci-thaijo.org/index.php/anres/article/view/243886.