If an author is no longer around how do you find the current rights holder? Ihave tried to find the current owners of some of Bud Caddell's plans that appeared in Scale RC Modeler in the 80's. Ican not find Bud, if he is still with us, and attempts to contact the publisher have yielded no replies.

With that said, how do you find the current copyright holder(s) of an article or plan?