Mohd Yusoff, Z., and A. H. Abdullah. “PEMIMPIN MENURUT PANDANGAN HAMKA: SATU TINJAUAN DALAM TAFSIR AL-AZHAR (Leadership According to HAMKA: A Review on Tafsir Al-Azhar)”. Journal of Al-Tamaddun, vol. 8, no. 1, June 2013, pp. 17-38, http://ijps.um.edu.my/index.php/JAT/article/view/8647.