Citazione APA

Hawking,Stephen, & Penrose,Roger. (1999). The Nature of Space and Time. OUP.

Stile di citazione Chicago

Hawking,Stephen, e Penrose,Roger. The Nature of Space and Time. Delhi: OUP, 1999.

Citazione MLA

Hawking,Stephen, e Penrose,Roger. The Nature of Space and Time. OUP, 1999.