Al-Fatlawi SMK. The Factors Contributing to Wastage of Instructional Time as Perceived by Principals of Popular Schools in Derna . mjssc [Internet]. 2012 Dec. 31 [cited 2025 Dec. 15];13(1):85-107. Available from: https://mdp.omu.edu.ly/journals/index.php/mjssc/article/view/392