需要订阅或英国公共图书馆会员资格 Boardman, Stephen, TheEarly Stewart Kings: Robert II and Robert III, 1371–1406, The Stewart Dynasty inScotland Series, Edinburgh: John Donald
114: "[…] the Grand Canal, dug between 605 and 609 by means of enormous levies of conscripted labour." The Other Europe intheMiddleages: Avars, Bulgars