Masturi, C. , Ikhsan, M. and Ahmad, A. (trans.) (2020) “The Improvement of Mathematical Problem Solving Ability and Self-Efficacy Students through Problem-Based Learning Model”, International Journal of Scientific Research and Management (IJSRM), 8(05), pp. 1408–1413. doi:10.18535/ijsrm/v8i05.el05.