using the MathSciNet reference database. Unfortuately, it is only accessible to MathSciNet subscribers, so basically on all university campuses or libraries.
IMDB, which started in the days of Usenet, was founded on user contributions. In today's parlance, it's built from user generated content (UGC).
It would be surprising to see any suit to enforce the licensing restrictions on a database built from user contributions like IMDB actually go to trial.
We might come away with some interesting answers to the questions of what licensing terms on such databases are truly enforceable (as opposed to mere intimidation).
What happened to that Craigslist lawsuit? How is that progressing?
http://www.ams.org/mathscinet/collaborationDistance.html
using the MathSciNet reference database. Unfortuately, it is only accessible to MathSciNet subscribers, so basically on all university campuses or libraries.
My Erdos number is no higher than 5 :-).