APA (7th ed.) Citation

(1951). JRO-Spezialkarte Ruhrgebiet. JRO-Verl.

Chicago Style (17th ed.) Citation

JRO-Spezialkarte Ruhrgebiet. München: JRO-Verl, 1951.

MLA (9th ed.) Citation

JRO-Spezialkarte Ruhrgebiet. JRO-Verl, 1951.

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