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