Mang’eni, Gladys N., et al. “ Effective Practical Work on Physics Students’ Performance in National Examinationat Selected Schools in Sirisia Division, Bungoma West Sub-County, Kenya ”. African Journal of Education,Science and Technology (AJEST), vol. 4, no. 4, Dec. 2018, pp. pp 301-311, http://ajest.org/index.php/ajest/article/view/729.