APA (7th ed.) Citation

Müller-Graff, P. (1998). Whose responsibilities are frontiers? The frontiers of Europe.

Chicago Style (17th ed.) Citation

Müller-Graff, Peter-Christian. "Whose Responsibilities Are Frontiers?" The Frontiers of Europe 1998.

MLA (9th ed.) Citation

Müller-Graff, Peter-Christian. "Whose Responsibilities Are Frontiers?" The Frontiers of Europe, 1998.

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