Kiriakidis, Peter, James William Decosta, and Antonio Sandu. 2011. “What Is the Effect of Grade Point Average (GPA) on Courses Taken Either Face-to-Face or Online by Undergraduate Working Adult Students?”. Revista de Cercetare Si Interventie Sociala 33 (June): 7-26. https://www.rcis.ro/journal/article/view/338-what-is-the-effect-of-grade-point-average-gpa-on-courses.