Abdul Hamid, S., and H. H. Mudasir. “An Exploratory Study on The Managerial Ownership and the Informativeness of Earnings in the Trading and Services Sector: An Evidence from Malaysia”. The Journal of Muamalat and Islamic Finance Research, vol. 2, no. 1, Jan. 2005, pp. 93-112, https://jmifr.usim.edu.my/index.php/jmifr/article/view/39.