PREDICTING PERFORMANCE OF FRONTLINER: ASSESSING THE ROLES OF MOTIVATION, WORK DISCIPLINE, ENVIRONMENT PT KERETA API PARIWISATA DAOP VI YOGYAKARTA. jopt [Internet]. 2026 Jul. 8 [cited 2026 Oct. 3];23(1):1-16. Available from: https://jurnal.stieieu.ac.id/index.php/opt/article/view/191