Rahayu, P. “Evaluating Service Quality: A Qualitative Analysis of Suroboyo Bus Services on the Purabaya - Rajawali Route in Surabaya City”. Jurnal Ilmiah Manajemen Kesatuan, vol. 11, no. 3, Dec. 2023, pp. 1271-8, https://jurnal.ibik.ac.id/index.php/jimkes/article/view/2269.