Cita APA (7a ed.)

Hubble, E. (1936). The realm of the nebulae. Oxford University Press.

Cita Chicago Style (17a ed.)

Hubble, Edwin. The Realm of the Nebulae. Oxford: Oxford University Press, 1936.

Cita MLA (9a ed.)

Hubble, Edwin. The Realm of the Nebulae. Oxford University Press, 1936.