ANOUVONG, P., L. BOUALONG, P. PONGNATHY, M. KEOPHATSADA, and S. KEOVIENGKHON. “The Efficiency of Web-Based Instruction by Google Classroom on 1st-Order Ordinally Deferential Equation at Faculty of Education, National University of Laos”. Souphanouvong University Journal Multidisciplinary Research and Development, vol. 8, no. 1, June 2022, pp. 208-16, http://www.su-journal.com/index.php/su/article/view/186.