APA (7th ed.) Citation

Sotheby's (Firm). (1989). Deutsche kunst des 20 jahrhunderts. Sotheby.

Chicago Style (17th ed.) Citation

Sotheby's (Firm). Deutsche Kunst Des 20 Jahrhunderts. Munich: Sotheby, 1989.

MLA (9th ed.) Citation

Sotheby's (Firm). Deutsche Kunst Des 20 Jahrhunderts. Sotheby, 1989.

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