Leton, S. I., M. Lakapu, dan W. B. N. Dosinaeng. “Mathematical Problem-Solving Abilities of Deaf Student in Solving Non-Routine Problems”. Math Didactic: Jurnal Pendidikan Matematika, Vol. 5, no. 2, Juli 2019, hlm. 157-6, doi:10.33654/math.v5i2.538.