MLA

Bär, Christian, and Klaus Fredenhagen. Quantum Field Theory On Curved Spacetimes. Springer Berlin / Heidelberg, 2009.

APA

Bär, C., & Fredenhagen, K. (2009). Quantum Field Theory on Curved Spacetimes. Springer Berlin / Heidelberg.

Chicago

Bär, Christian, Christian Bär, and Klaus Fredenhagen. Quantum Field Theory On Curved Spacetimes. : Springer Berlin / Heidelberg, 2009.