Salisu, M. . “The Art of Composing a Formal Letter from the Perspective of Qur’anic Literature: The Case of King Solomon’s Letter to Queen Sheba: Qur’anic Literature”. Al-Ḍād Journal, vol. 5, no. 1, Nov. 2021, pp. 27-38, http://adum.um.edu.my/index.php/aldaad/article/view/33461.