Cita APA

Sandage, A., & Hubble, E. P. (1961). The Hubble atlas of galaxies. Washington: Carnegie Institution of Washington.

Citación estilo Chicago

Sandage, Allan, y Edwin Powell Hubble. The Hubble Atlas of Galaxies. Washington: Carnegie Institution of Washington, 1961.

Cita MLA

Sandage, Allan, y Edwin Powell Hubble. The Hubble Atlas of Galaxies. Washington: Carnegie Institution of Washington, 1961.