“Pengembangan Perangkat Pembelajaran Matematika Model Pembelajaran Berbasis Masalah untuk Meningkatkan Kualitas Proses dan Hasil Belajar di SMP: Developing of Mathematics Learning Devices with Problem Based Learning Model to Improve Process Quality and Learning Outcomes of Junior High School”, st, vol. 2, no. 2, Jul. 2019, doi: 10.32734/st.v2i2.544.