VONGVIZAY, P., B. VONGTONGKHAM, and M. MINGKEO. “Design of Experimental Series on the Free Fall of Object: https://doi.Org/10.69692/SUJMRD0802236”. Souphanouvong University Journal Multidisciplinary Research and Development, vol. 8, no. 2, Dec. 2022, pp. 236-43, http://www.su-journal.com/index.php/su/article/view/222.