APA (7th ed.) Citation

Falkenstein, L. (1998). Otto III. und Aachen. Monumenta Germaniae historica.

Chicago Style (17th ed.) Citation

Falkenstein, Ludwig. "Otto III. Und Aachen." Monumenta Germaniae Historica 1998.

MLA (9th ed.) Citation

Falkenstein, Ludwig. "Otto III. Und Aachen." Monumenta Germaniae Historica, 1998.

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