對於這一切,見Duncan,Scotland: The Making of the Kingdom,第134頁、第217–218頁、223頁;亦參,Durham and part of the earldomof Northumberland in the eyes of Earl Henry, Paul Dalton,"Scottish
Oram, Richard D., "The Earls and Earldomof Mar, c. 1150–1300", Steve Boardman and Alasdair Ross (eds.) The Exercise of Power in Medieval Scotland, c. 1200–1500