SALWA, Aprilia Eka; SYAHRIL, Syahril; INDRAWAN, Eko; KASSYMOVA, Gulzhaina K. Problem-based learning in orthogonal projection drawing: A quasi-experimental study on vocational machining students’ technical drawing achievement. Jurnal Pendidikan Teknologi Kejuruan, Padang, Indonesia, v. 9, n. 2, p. 146–160, 2026. DOI: 10.24036/jptk.v9i2.50323. Disponível em: https://jptk.ppj.unp.ac.id/index.php/jptk/article/view/503. Acesso em: 14 jul. 2026.