British Kings and Queens @ p. 173
The cited information was published by 1998, Barnes and Nobles (Ref: p. 173) The author/originator was Mike Ashley.
References (3)
Parent Source:
British Kings and Queens
Individual:
King Nechtan Mawr MacErb II of the Picts
Individual:
King Erb ap Erbic of Glywyssing & Gwent