Fitriansyah, Ayu. “The Description of Diphtheria Immunization History to Diphtheria Patients in Surabaya at 2017”. Jurnal Berkala Epidemiologi 6, no. 2 (August 30, 2018): 103–111. Accessed December 2, 2024. https://e-journal.unair.ac.id/JBE/article/view/7994.