The length of his reign is based on the various Pictish king lists, where he is associated with Talorgan son of Uuthoil. Some sources, such as John of Fordun, conflate the two kings as "Durstolorger", perhaps under the influence of the earlier "Dubthalorc".
It was once thought that Pictish kings in this period were also kings of Dál Riata, but this is no longer supported.
- Anderson, Alan Orr, Early Sources of Scottish History A.D 500–1286, volume 1. Reprinted with corrections. Paul Watkins, Stamford, 1990. ISBN 1-871615-03-8
- Broun, Dauvit. "Pictish Kings 761-839: Integration with Dál Riata or Separate Development" in Sally Foster (ed.) The St Andrews Sarcophagus: A Pictish masterpiece and its international connections. Dublin: Four Courts Press, 1998. ISBN 1-85182-414-6
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