Fatchurrohmah, A., S. Sarwi, and U. Utsman. “Pengaruh Problem Based Learning Melalui Demonstrasi Dan Diskusi Terhadap Kemampuan Verbal”. Journal of Primary Education, Vol. 6, no. 2, Sept. 2017, pp. 140-6, doi:10.15294/jpe.v6i2.17567.