APA (7th ed.) Citation

Zabehlicky, H., & Zabehlicky, S. "WO WAR DIE GRENZE?".

Chicago Style (17th ed.) Citation

Zabehlicky, Heinrich, and Susanne Zabehlicky. "WO WAR DIE GRENZE?".

MLA (9th ed.) Citation

Zabehlicky, Heinrich, and Susanne Zabehlicky. "WO WAR DIE GRENZE?".

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