Schaefer, B. E. (2003). Old Astrophotos: Averting a lost lega cy ; Yersterday's astronomical photographs can still produce cutting-edge science - but only if we preserve them for tomorrow's astronomers. Sky & Telescope.
Chicago-viite (17. p.)Schaefer, Bradley E. "Old Astrophotos: Averting a Lost Lega Cy ; Yersterday's Astronomical Photographs Can Still Produce Cutting-edge Science - but Only If We Preserve Them for Tomorrow's Astronomers." Sky & Telescope 2003.
MLA-viite (8. p.)Schaefer, Bradley E. "Old Astrophotos: Averting a Lost Lega Cy ; Yersterday's Astronomical Photographs Can Still Produce Cutting-edge Science - but Only If We Preserve Them for Tomorrow's Astronomers." Sky & Telescope, 2003.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.