APA (7th ed.) Citation

Baumann, O., Baumann, M., Baumann, H., & Freymadl, W. Regensburg: Otto Baumann : Regensburg 1901-1992.

Chicago Style (17th ed.) Citation

Baumann, Otto, Marianne Baumann, Hildegard Baumann, and Walter Freymadl. Regensburg: Otto Baumann : Regensburg 1901-1992.

MLA (9th ed.) Citation

Baumann, Otto, et al. Regensburg: Otto Baumann : Regensburg 1901-1992.