Lyon 1980, pp. 62–63. Lyon, Bryce (1980). A Constitutional and Legal History of Medieval England (2nd ed.). W. W. Norton & Company. ISBN0-393-95132-4. 1st edition available to read online here.
Lyon 1980, p. 63. Lyon, Bryce (1980). A Constitutional and Legal History of Medieval England (2nd ed.). W. W. Norton & Company. ISBN0-393-95132-4. 1st edition available to read online here.