Kusbaryanto, -. “The Correlation of Education about Cough Etiquette and the Knowledge of Security Officers and Cleaning Service Officers”. International Journal of Human and Health Sciences (IJHHS) 3, no. 1 (November 2, 2018): 23–25. Accessed November 5, 2025. https://ijhhsfimaweb.info/IJHHS/article/view/69.