Cita APA

Christopher, C., & Jonh Christopher. (2000). Return to earth. New York, Random House: Oxford University Press.

Chicago Style Citation

Christopher, Christopher, i Jonh Christopher. Return to Earth. New York, Random House: Oxford University Press, 2000.

Cita MLA

Christopher, Christopher, i Jonh Christopher. Return to Earth. New York, Random House: Oxford University Press, 2000.