extragalactique

[2008] Beyond the Galaxy: the development of extragalactic astronomy 1885 - 1965 Part 1 ; Robert W. Smith ; Journal for the History of Astronomy 39 (2008) p. 91 [lien]
[2009] Beyond the Galaxy: The Development of Extragalactic Astronomy 1885-1965: Part 2 ; Robert W. Smith ; Journal for the History of Astronomy 40 (2009) p. 71 [lien]