APA (7th ed.) Citation

Schieffer, R. (1991). Johannes XI., Papst (931-936).

Chicago Style (17th ed.) Citation

Schieffer, Rudolf. Johannes XI., Papst (931-936). 1991.

MLA (9th ed.) Citation

Schieffer, Rudolf. Johannes XI., Papst (931-936). 1991.

Warning: These citations may not always be 100% accurate.