APA (7th ed.) Citation

Kotrba, E., & Premstaller, O. (1959). Ex Libris Ottmar Premstaller.

Chicago Style (17th ed.) Citation

Kotrba, Emil, and Ottmar Premstaller. Ex Libris Ottmar Premstaller. [S. l.], 1959.

MLA (9th ed.) Citation

Kotrba, Emil, and Ottmar Premstaller. Ex Libris Ottmar Premstaller. 1959.

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