Mandag, H., and T. Sandari. “Studi Kasus : Implementasi System Whistleblowing Untuk Mengungkap Fraud Di Pt. Kereta Api Indonesia Daop Viii Surabaya”. Jurnal Ilmiah Wahana Pendidikan, Vol. 11, no. 8.C, Aug. 2025, pp. 69-75, https://jurnal.peneliti.net/index.php/JIWP/article/view/11186.