APA (7th ed.) Citation

Gilles, W., & Ruhrberg, K. (1962). Werner Gilles: Karl Ruhrberg. Bongers.

Chicago Style (17th ed.) Citation

Gilles, Werner, and Karl Ruhrberg. Werner Gilles: Karl Ruhrberg. Recklinghausen: Bongers, 1962.

MLA (8th ed.) Citation

Gilles, Werner, and Karl Ruhrberg. Werner Gilles: Karl Ruhrberg. Bongers, 1962.