Chaijaroonkhanarak, W., W. Woraputtaporn, P. Amarttayakong, J. Umka, K. Brown, W. Pannangrong, and M. Namking. “Length, Diameter and Variation of Types of Portal Vein Formation in Northeastern Thais”. Srinagarind Medical Journal, vol. 25, no. 4, Oct. 2013, pp. 323-7, https://li01.tci-thaijo.org/index.php/SRIMEDJ/article/view/12958.