It's pretty easy to Google this stuff , so i would assume you have already done this
COPYRIGHT TERMINATION:
HOW AUTHORS (AND THEIR HEIRS) CAN
RECAPTURE THEIR PRE-1978 COPYRIGHTS By Attorney Lloyd J. Jassin
To protect authors of older works from having to “live” with a bad deal they entered into when they had little negotiating skill or leverage, the Copyright Act provides that at the end of 56 years, the author (or if the author is dead, his wife and children or grandchildren), can recapture the last 39 years of copyright. For example, a publishing contract signed in 1948 can be terminated in 2004, provided timely notice of termination is given. As long as the work is not a “work made for hire,” the right of termination cannot be waived -- even if there are contractual provisions to the contrary.
The Copyright Act also gives families of deceased authors another opportunity to extract value from copyrighted works. When the author of an older work dies during the initial 28-year term of copyright, that author’s family has the right to reclaim his or her renewal copyright -- a further term of 67 years of copyright protection. This added opportunity to get back ownership of copyrights exists even if the author assigned his or her renewal term (or devised it by will) to someone other than his or her family.
The Devil is in the Details The manner in which notice of termination is given is highly technical and beyond the scope of this article. For example, notice provided prematurely, or too late, can frustrate your efforts to recapture rights. Besides the author’s widow or widower, children and grandchildren, the Copyright Act also permits termination rights to be exercised by an author’s executor, administrator or personal administrator, provided there is no spouse, children or grandchildren. Also, in situations where there are multiple authors, or after the death of an author, more than one individual may hold the right to terminate. In addition, termination notices must be recorded with the Copyright Office prior to the date of termination.