Alfarhan , I. . “The Effectiveness of Teaching Science Using Needham’s Structural Model in Developing Levels of Cognitive Depth and Critical Thinking Skills of Sixth Grade Students”. Dirasat: Educational Sciences, vol. 47, no. 4, Dec. 2020, pp. 104-23, http://dsr.ju.edu.jo/djournals/index.php/Edu/article/view/2445.