OttoBib was created by Jonathan Otto in 2006 and his brother Nick started helping in 2012.
The idea for this site came from Seth Godin's blog post about "Stuck Systems".
Seth outlined 2 requirements:
What is an ISBN? - The International Standard Book Number, or ISBN (sometimes pronounced "is-ben"), is a unique identifier for books. (Wikipedia.org)
As of January 2007 you can lookup individual citations. I encourage other websites to incorporate this feature.
http://www.ottobib.com/isbn/0195117972 for MLA, APA, Chicago, BibTeX and Wikipedia.
Tell others about OttoBib if you found it useful, otherwise email me: email@example.com with ideas on how to improve it.