Choavaratana, R. ., D. . Manoch, and S. . Panyathaweesap. “Effect of Pentoxifylline on Human Sperm Preparation”. Siriraj Medical Journal, vol. 55, no. 9, Sept. 2003, pp. 534-8, https://he02.tci-thaijo.org/index.php/sirirajmedj/article/view/245447.