Laokirkkiat, P., D. Manoch, S. Changeakwong, and S. Kunathikom. “Sperm Motility and Morphology after Preparation Using the Percoll Gradient Method Compared with the IxaPrep Gradient Method”. Siriraj Medical Journal, vol. 55, no. 1, Jan. 2003, pp. 1-5, https://he02.tci-thaijo.org/index.php/sirirajmedj/article/view/245370.