APA (7th ed.) Citation

Borchardt, E., & Borchardt, J. (1991). Friedrich Wilhelm: Sohn Friedrichs.

Chicago Style (17th ed.) Citation

Borchardt, Erika, and Jürgen Borchardt. Friedrich Wilhelm: Sohn Friedrichs. 1991.

MLA (9th ed.) Citation

Borchardt, Erika, and Jürgen Borchardt. Friedrich Wilhelm: Sohn Friedrichs. 1991.

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