Tyson, N. D. G. (1994). Universe down to Earth. Columbia University Press.
Cita Chicago (17th ed.)Tyson, Neil De Grasse. Universe Down to Earth. New York: Columbia University Press, 1994.
Cita MLA (9th ed.)Tyson, Neil De Grasse. Universe Down to Earth. Columbia University Press, 1994.
Atenció: Aquestes cites poden no estar 100% correctes.