APA (7th ed.) Citation

Maas, W. (1961). Probleme der Sozialgeographie. Duncker & Humblot.

Chicago Style (17th ed.) Citation

Maas, Walther. Probleme Der Sozialgeographie. Berlin: Duncker & Humblot, 1961.

MLA (9th ed.) Citation

Maas, Walther. Probleme Der Sozialgeographie. Duncker & Humblot, 1961.

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