http://hometown.aol.com/ttrim36387/douglas.html
http://www.sjana.net/table1.html:
The above table is compiled from a synthesis of the traditional pedigrees recorded in the "Anglo-Saxon Chronicle", and Bede, Florence of Worcester, and other early historians. Although it probably embodies much genuine material it must be accepted and used with great caution. In some cases names have obviously been omitted, while in others they have been duplicated and, in the case of Wessex in particular, interpolated to bring together two distinct traditions.-Kings & Queens of Britain by David Williamson, Page 212, Appendix B: Genealogical Tables