Credit must be given to the works listed below, without which this website could not have been possible:
The Washington Double Star Catalog (cited as WDSC) maintained at the U.S. Naval Observatory.
The Cambridge Double Star Atlas (cited as CDSA), James Mullaney and Wil Tirion (Cambridge University Press, online edition, 2013)
Field Guide to the Deep Sky Objects, Mike Inglis (London, 2001)
Burnham's Celestial Handbook, Robert Burnham (NY, 1978)
The Flamsteed Collection, Richard Dibon-Smith (Toronto, 1998)
STARS (http://stars.astro.illinois.edu/sow/sowlist.html) created by Jim Kaler
SEDS, The Messier Catalogue (http://messier.seds.org)