Cita APA

Sparker, L. S., & Gallagher, J. S. (2007). Galaxies in the universe: An introduction (2a. ed.). Cambridge University Press.

Citación estilo Chicago

Sparker, Linda S., and John S. Gallagher. Galaxies in the Universe: An Introduction. 2a. ed. Nueva York: Cambridge University Press, 2007.

Cita MLA

Sparker, Linda S., and John S. Gallagher. Galaxies in the Universe: An Introduction. 2a. ed. Cambridge University Press, 2007.