Cita APA

Sagan, C. (1997). Billions and billions: Thoughts on life and death at the brink of the millennium (First edition.). New York: Random House.

Citación estilo Chicago

Sagan, Carl. Billions and Billions: Thoughts On Life and Death At the Brink of the Millennium. First edition. New York: Random House, 1997.

Cita MLA

Sagan, Carl. Billions and Billions: Thoughts On Life and Death At the Brink of the Millennium. First edition. New York: Random House, 1997.