Ismail, A. G., M. Ma’in, and N. Ahmat. “The Impact of Leverage on Investment: Evidence from Shariah Listed Firms”. The Journal of Muamalat and Islamic Finance Research, vol. 8, no. 1, Jan. 2011, pp. 105-20, https://jmifr.usim.edu.my/index.php/jmifr/article/view/134.