Srinoy Chumkam, J.T. Yu, and Chanvit Vajrabukkal. 1993. “Effects of Handling Stress of Gilts During Gestation on Embryonic Survival”. Agriculture and Natural Resources 27 (4). Bangkok, Thailand:516-19. https://li01.tci-thaijo.org/index.php/anres/article/view/241707.