Mann, Horace Kinder (1906). The Lives of the Popes in the Early Middle Ages. Vol. 5: The Popes In The Days of Feudal Anarchy, from Formosus to Damasus II, Part 2. London: Kegan Paul, Trench, Trubner & Co. p. 124.
Manfred Agethen. "Ackermann, Else * 6.11.1933 CDU-Reformerin". Wer war wer in der DDR?. Ch. Links Verlag, Berlin & Bundesstiftung zur Aufarbeitung der SED-Diktatur, Berlin. Retrieved 1 January 2018.