Soucek, Svat (1994), "Piri Reis and Ottoman Discovery of the Great Discoveries", Studia Islamica, 79 (79): 121–142 [123 & 134–6], doi:10.2307/1595839, JSTOR1595839
Soucek, Svat (1994), "Piri Reis and Ottoman Discovery of the Great Discoveries", Studia Islamica, 79 (79): 121–142 [123 & 134–6], doi:10.2307/1595839, JSTOR1595839
saudiaramcoworld.com
Covington, Richard (2007), "The Third Dimension", Saudi Aramco World, May-June 2007: 17–21, archived from the original on 2018-12-25, retrieved 2008-07-06
web.archive.org
Covington, Richard (2007), "The Third Dimension", Saudi Aramco World, May-June 2007: 17–21, archived from the original on 2018-12-25, retrieved 2008-07-06