Islamic Seals Database, Chester Beatty Library Dublin, 2011-. Crowd-sourced cataloging project whose website (http://www.cbl.ie/islamicseals/Home.aspx) has been under reconstruction since the end of 2018; an archived version is available through the Wayback Machine: https://web.archive.org/web/20180903071332/http://www.cbl.ie/islamicseals/Home.aspx
Ottoman Sultan Tugras, 2002. The Turkish-English website is a labor of love project of Ercan Mensiz; available at: http://www.tugra.org
See also Günay Kut and Nimet Bayraktar, Yazma eserlerde vakıf mühürleri, 1st ed., Ankara: Kültür ve Turizm Bakanlığı Yayınları, 1984.
Dagmar A. Riedel
First published, 13 April 2013
Last updated, 25 August 2021