Mutanyatta, Johannes. “Formative Evaluation of Distance Education::A Case Study of the Certificate in Adult Education at the University of Botswana”. International Journal of E-Learning & Distance Education Revue Internationale Du E-Learning Et La Formation à Distance, vol. 4, no. 1, Mar. 1989, pp. 36-45, https://ijede.ca/index.php/jde/article/view/355.