Yahya, Ahmad, and Imas Maesaroh. 2021. “Standard Operational Procedures for Congregational Services During The Covid-19 Pandemic at The Head Office Of Shafira Tour Travel Surabaya.”. Proceedings of International Conference on Da’wa and Communication 3 (1), 336-44. https://proceedings.uinsa.ac.id/index.php/ICONDAC/article/view/666.