Kartin Usman, Abdul Wahab Abdullah, Abas Kaluku, Tristanti Anggraini Usman. “The Effect of Problem Based Learning Model on Students’ Mathematical Problem Solving Ability on Social Arithmetic Materials at SMP Negeri 2 Limboto”. Turkish Journal of Computer and Mathematics Education (TURCOMAT), vol. 12, no. 14, Aug. 2021, pp. 1683-92, doi:10.17762/turcomat.v12i14.10512.