Book publishers

I wanted to do the same thing. I contacted the author of a book and he had no idea. Here is what he said. "Most of that company was sold in the mid 1980s and I don't know which company, if any, ended up with the copyrights to the books. It might reside with Penton Media (headquartered in Cleveland) since they acquired in 1989 most of properties that were first sold to VNU, a Dutch publishing company in 1986. I don't know if the Book division was part of those sales or if it was just disbanded or sold to yet another publishing company in 1986." If you ask any of those companies, they will assume they do own the rights and just say "NO". Here is what the US copyright office says: "How can I find out who owns a copyright? We can provide you with the information available in our records. A search of registrations, renewals, and recorded transfers of ownership made before 1978 requires a manual search of our files. Upon request, our staff will search our records at the statutory rate of $150 for each hour. There is no fee if you conduct a search in person at the Copyright Office. Copyright registrations made and documents recorded from 1978 to date are available for searching online. For further information, see Circular 22, How to Investigate the Copyright Status of a Work, and Circular 23, Copyright Card Catalog and the Online File." My question would be...if the company that produced the book no longer exists and no one bothered to get the copyright renewed...then is the book public domain or at least owned by the author?