as a reference librarian, i feel like i SHOULD know the answer to this
right off the top of my head, but my cpu seems to have suffered a RAM
crash:
 
i got a call yesterday from a fellow who's looking to find out what
films are in the public domain so that he may use images from them in a
corporate presentation.  do any of my estimable screen-ellers know of
a printed source for such things, or should i count on the fact that films
56 years old, and older (the "28+28" copyright renewal), are safe to
cull from without obtaining permission from the copyright holder?
 
perspiring minds want to know.  to save bandwidth, i invite you to send
answers to me, rather than to the list.  thanks.
larry schwartz, theatre/film librarian, southern meth u, dallas(?), texas(??)