Etra (starogrčki: Αἴθρα , "svijetlo nebo")^[1][2] u grčkoj mitologiji bila je jedna od 3.000 Okeanida, kćeri Okeana i Tetide.^[3] Ponekad se naziva ženom Atlasa i majkom Plejada, Hijada (češće potomaka Plejone) i Hijanta.^[2][4][5]

• Apollodorus, The Library with an English Translation by Sir James George Frazer, F.B.A., F.R.S. in 2 Volumes, Cambridge, MA, Harvard University Press; London, William Heinemann Ltd. 1921. ISBN 0-674-99135-4. Online version at the Perseus Digital Library. Greek text available from the same website.
• Bell, Robert E., Women of Classical Mythology: A Biographical Dictionary. ABC-Clio. 1991. ISBN 9780874365818.
• Gaius Julius Hyginus, Astronomica from The Myths of Hyginus translated and edited by Mary Grant. University of Kansas Publications in Humanistic Studies. Online version at the Topos Text Project.
• Gaius Julius Hyginus, Fabulae from The Myths of Hyginus translated and edited by Mary Grant. University of Kansas Publications in Humanistic Studies. Online version at the Topos Text Project.
• Graves, Robert, The Greek Myths, Harmondsworth, London, England, Penguin Books, 1960. ISBN 978-0143106715
• Homer, The Iliad with an English Translation by A.T. Murray, Ph.D. in two volumes. Cambridge, MA., Harvard University Press; London, William Heinemann, Ltd. 1924. ISBN 978-0674995796. Online version at the Perseus Digital Library.
• Homer, Homeri Opera in five volumes. Oxford, Oxford University Press. 1920. ISBN 978-0198145318. Greek text available at the Perseus Digital Library.
• Lucius Mestrius Plutarchus, Lives with an English Translation by Bernadotte Perrin. Cambridge, MA. Harvard University Press. London. William Heinemann Ltd. 1914. 1. Online version at the Perseus Digital Library. Greek text available from the same website.
• Pausanias, Description of Greece with an English Translation by W.H.S. Jones, Litt.D., and H.A. Ormerod, M.A., in 4 Volumes. Cambridge, MA, Harvard University Press; London, William Heinemann Ltd. 1918. ISBN 0-674-99328-4. Online version at the Perseus Digital Library
• Pausanias, Graeciae Descriptio. 3 vols. Leipzig, Teubner. 1903. Greek text available at the Perseus Digital Library.
• Publius Ovidius Naso, Fasti translated by James G. Frazer. Online version at the Topos Text Project.
• Publius Ovidius Naso, Fasti. Sir James George Frazer. London; Cambridge, MA. William Heinemann Ltd.; Harvard University Press. 1933. Latin text available at the Perseus Digital Library.