Edward Castronova:Synthetic Worlds: The Business and Culture of Online Games. University Of Chicago Press, 2006, ISBN 978-0-226-09627-8 (englisch, archive.org): “[S. 10] The ancestors of MMORPGS were text-based multiuser domains (MUDs) [...], [S. 291] Indeed, MUDs generate perhaps the one historical connection between game-based VR and the traditional program [...]”
T.L. Taylor:Play Between Worlds: Exploring Online Game Culture. The MIT Press, 2006, ISBN 978-0-262-20163-6, S.24 (englisch, archive.org).
Randolph Carter:Psychochild.In:Grinding to Valhalla.23.April 2009,abgerufen am 31.Januar 2021:„The MUDs I played extensively: Genocide (where I first used the name "Psychochild"), Highlands, Farside, Kerovnia, and Astaria.“
Richard Bartle:Interactive Multi-User Computer Games.1990,archiviertvomOriginalam2.Februar 2016;abgerufen am 31.Januar 2021:„The Multi-User Galaxy Game project was begun in 1985 by CompuNet as a SF alternative to MUD1, which then ran on the system. When the other programmer left CompuNet, Lenton rewrote the game from scratch as Federation II. It was officially launched on CompuNet in 1989; reported also to run on MicroLink, and on any other commercial system willing to take it.“
Mike Nelson:Interview: Brad McQuaid.In:The guru of 3D.2.Juli 2002,archiviertvomOriginalam10.März 2007;abgerufen am 31.Januar 2021.
Keith Stuart:MUD, PLATO and the dawn of MMORPGs.In:The Guardian.17.Juli 2007,abgerufen am 31.Januar 2021:„The thing is, though, that even if the likes of Oubliette did count as a virtual world, they had pretty well zero effect on the development of today's virtual worlds. Follow the audit trail back from World of Warcraft, and you wind up at MUD.“
Richard Bartle:Interactive Multi-User Computer Games.1990,archiviertvomOriginalam2.Februar 2016;abgerufen am 31.Januar 2021:„The Multi-User Galaxy Game project was begun in 1985 by CompuNet as a SF alternative to MUD1, which then ran on the system. When the other programmer left CompuNet, Lenton rewrote the game from scratch as Federation II. It was officially launched on CompuNet in 1989; reported also to run on MicroLink, and on any other commercial system willing to take it.“
Mike Nelson:Interview: Brad McQuaid.In:The guru of 3D.2.Juli 2002,archiviertvomOriginalam10.März 2007;abgerufen am 31.Januar 2021.