Lothong, M., K. Tachampa, P. Assavacheep, and K. Angkanaporn. “Effects of Dietary Betaine Supplementation on Back Fat Thickness and Serum IGF-1 in Late Finishing Pigs”. The Thai Journal of Veterinary Medicine, vol. 46, no. 3, Oct. 2016, pp. 427-34, https://he01.tci-thaijo.org/index.php/tjvm/article/view/69530.