Yunisa, . A. Y., and . B. . Yunisa,. “Opportunities and Challenges of Optimized Method of Teaching Using Virtual Classroom Instructional Technology During Covid-19 Pandemic in Public Secondary Schools in Nigeria”. Kashere Journal of Education, vol. 2, no. 1, June 2021, pp. 121-8, https://journals.fukashere.edu.ng/index.php/kje/article/view/617.