Al-Kaabi, Abed Al-Hakim. “Building of Commercial Ships in the Middle Age. A Comparative Study Between the Ships That Were Built in the Mediterranean and Those Built in the Indian Ocean”. Al-Balqa Journal for Research and Studies, vol. 8, no. 1, June 2001, pp. 36-49, https://ajrs.ammanu.edu.jo/ojs/index.php/albalqajournal/article/view/447.