Development and Evaluation of i-Mutawwif: A Mobile Language Traveller Guide in Arabic for Mutawwif (Umrah Tour Guide). - Muhammad Sabri bin Sahrir; Mohd Firdaus Yahaya; Taufik Ismail; Muhamad Azhar Zubir; Wan Rusli Wan Ahmad (Int. J. Interact. Mob. Technol., 2018)