Hassan, Dr. Atif, et al. “LEARNING ENGAGEMENT SCALE (LES): DEVELOPMENT OF A COMPOSITE MEASURE AND ANALYSIS OF PSYCHOMETRIC PROPERTIES FOR BUSINESS SCHOOLS”. Journal of Business Strategies, vol. 14, no. 2, Dec. 2020, pp. 38-68, http://greenwichjournals.com/index.php/businessstudies/article/view/497.