Abeysinghe AMPB, Jayatilleke BG, Athapattu BCL, Gamini LPS. Costing of a Blended Course at the Open University of Sri Lanka: An Empirical Study. IJSBAR. 2015;24(1):37-50. Accessed December 3, 2025. https://gssrr.org/JournalOfBasicAndApplied/article/view/4189