Napitupulu, M. F. L., G. Arini, and S. S. Ayutthaya. “Risk Factors and Aftermath of Stress on Female Commercial Flight Attendants in Indonesia”. Majalah Kedokteran UKI, Vol. 34, no. 2, Nov. 2018, pp. 61-68, http://ejournal.uki.ac.id/index.php/mk/article/view/864.