Sailun B, Putri ME, Handayani P. AN ANALYSIS OF SCHOOL-WIDE TOKEN ECONOMY SYSTEM ON CHALLENGE BEHAVIOR OF MENTAL RETARDATION’ STUDENTS AT SLBN PENBINA PEKANBARU. Perspektif [Internet]. 2017 Sep. 23 [cited 2024 May 3];5(9). Available from: https://journal.uir.ac.id/index.php/Perspektif/article/view/734