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Edwin Hubble - NASA Science
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Hubble's Universe by Terence Dickinson - Ebook
Biography of Edwin Powell Hubble (1889 - 1953)
Edwin Hubble, the astronomer who discovered there are galaxies
Edwin Hubble - Biography, Facts and Pictures
Galaxies and the Universe - A Question and Answer Guide to Astronomy
The James Webb telescope: an eye onto a universe, infinite in time
Dec. 30, 1924: Hubble Reveals We Are Not Alone
The Backyard Astronomer's Guide by Terence Dickinson, Alan Dyer