1. The B-Book
2. Agda Development Team. The Agda Wiki. http://wiki.portal.chalmers.se/agda/pmwiki.php.
3. Crafting a Proof Assistant
4. Andrea Asperti and Bernd Wegner. MOWGLI - A New Approach for the Content Description in Digital Documents. InProc. of the 9th Intl. Conference on Electronic Resources and the Social Role of Libraries in the Future, volume 1, Autonomous Republic of Crimea, Ukraine, 2002.