Bekal0, S. A., and A. G. . Welford. “Practical Activity in Ethiopian Secondary Physical Sciences: Implications for Policy and Practice of the Match Between the Intended and Implemented Curriculum 1”. The Ethiopian Journal of Education, vol. 20, no. 2, Feb. 2021, pp. 91-133, http://213.55.95.79/index.php/EJE/article/view/577.