Blood Royal:  Issue of the Kings and Queens of Medieval England 1066-1399:  The Normans and Plantagenets @ p. 42, footnote 8

The cited information was published by Heritage Books, 1996 (Ref: p. 42, footnote 8) The author/originator was T. Anna Leese.
Blood Royal:  Issue of the Kings and Queens of Medieval England 1066-1399:  The Normans and Plantagenets. 

• Source Notes

  Only the first name is given in this source

• References (2)
  • Parent Source: Blood Royal:  Issue of the Kings and Queens of Medieval England 1066-1399:  The Normans and Plantagenets
  • Individual: Pribislaw of the Obotrites Prince