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 2019, 2 (2). https://doi.org/10.32734/st.v2i2.544.