Sangvichien, S. ., . O. . Putsom, and A. Chuncharunee. “Anatomical Variations of the Ansa Cervicalis in Thais”. Siriraj Medical Journal, vol. 55, no. 2, Feb. 2003, pp. 91-99, https://he02.tci-thaijo.org/index.php/sirirajmedj/article/view/245379.