Bresslau, Jahrbücher, I, p. 378; Creber, Alison (2019-04-22). «Breaking Up Is Hard To Do: Dissolving Royal and Noble Marriages in Eleventh-Century Germany» (στα αγγλικά). German History37 (2): 149–171. doi:10.1093/gerhis/ghy108. ISSN0266-3554.
Bresslau, Jahrbücher, I, p. 378; Creber, Alison (2019-04-22). «Breaking Up Is Hard To Do: Dissolving Royal and Noble Marriages in Eleventh-Century Germany» (στα αγγλικά). German History37 (2): 149–171. doi:10.1093/gerhis/ghy108. ISSN0266-3554.