M. S. . Sahrir, T. . Ismail, M. F. . Yahaya, and M. A. . Zubir, “An Insight into the Needs Analysis of the Mobile Language Traveller App Design For Mutawwif (Umrah Tour Guide) Via Mobile Platforms During COVID-19 Outbreak”, CIBG, vol. 27, no. 5, pp. 946–961, Oct. 2021.