Griffiths, R. A. The Later Middle Ages (1290 - 1485): Ralph A. Griffiths. The Oxford illustrated history of Britain.(1989).

Griffiths, Ralph A. "The Later Middle Ages (1290 - 1485): Ralph A. Griffiths." The Oxford Illustrated History of Britain.(1989) .

Griffiths, Ralph A. "The Later Middle Ages (1290 - 1485): Ralph A. Griffiths." The Oxford Illustrated History of Britain.(1989), .