APA način citiranja

Hawking, S. P. Nature of space and time. OUP.

Čikaški stil citiranja

Hawking, Stephen Penrose. Nature of Space and Time. OUP.

MLA način citiranja

Hawking, Stephen Penrose. Nature of Space and Time. OUP.

Upozorenje: Ovi citati možda nisu uvijek 100% točni.