Idrus Nabu, Sarson W. Pomalato, and Tedy Machmud, “DEVELOPMENT OF PROBLEM-BASED LEARNING DEVICES ON MATHEMATICS AND TRIANGLE MATERIALS FOR JUNIOR HIGH SCHOOL STUDENTS CLASS VII AT JUNIOR HIGH SCHOOL 5 PAGUYAMAN”, Euro. J. Hum. Edu. Adv., vol. 3, no. 8, pp. 186-193, Aug. 2022.