Ortigueza, M., G. Fernandez, M. Ulbinar, F.J. Mon, A.L. Quintal, and Franklin A. Sison, MBA. 2019. “An Office Procedure Study of Human Resource and Billing Department in MNO Company”. Ascendens Asia Singapore – Bestlink College of the Philippines Journal of Multidisciplinary Research 1 (1). https://ojs.aaresearchindex.com/index.php/aasgbcpjmra/article/view/1904.