University of British Columbia. Committee for Medieval Studies, Studies in medieval and renaissance history (неопр.). Архивировано 27 марта 2020 года., Committee for Medieval Studies, University of British Columbia, 1980, p. 159
University of British Columbia. Committee for Medieval Studies, Studies in medieval and renaissance history (неопр.). Архивировано 27 марта 2020 года., Committee for Medieval Studies, University of British Columbia, 1980, p. 159