The Hubble atlas of galaxies.
APA Citation
Sandage, A., Hubble, E. (1961). The Hubble atlas of galaxies. Washington: Carnegie Institution of Washington.
MLA Citation
Sandage, Allan, and Edwin Hubble. The Hubble Atlas of Galaxies. Washington: Carnegie Institution of Washington, 1961.
Warning: These citations may not always be complete (especially for serials).