Cita APA

(2007). 21st century astronomy: Stars and galaxies. New York: W.W. Norton.

Chicago Style Citation

21st Century Astronomy: Stars and Galaxies. New York: W.W. Norton, 2007.

Cita MLA

21st Century Astronomy: Stars and Galaxies. New York: W.W. Norton, 2007.

Atenció: Aquestes cites poden no estar 100% correctes.