Manansala, MJ. N., et al. “Airport Management System: Human Resource 3 (Time Sheet Management, Leave Management, Shift and Scheduling, Time and Attendance, Claims and Reimbursement)”. Ascendens Asia Singapore – Bestlink College of the Philippines Journal of Multidisciplinary Research, vol. 1, no. 1, Apr. 2019, https://ojs.aaresearchindex.com/index.php/aasgbcpjmra/article/view/2218.