Dozens of of obscure, out-of-print books are about to become much more accessible thanks to the Internet Archive, the digital archive of public domain media. But to do it, they’ll have to exploit a loophole in a controversial copyright law, as Ars Technica reports.

The Internet Archive is releasing the Sonny Bono Memorial Collection, a group of books from the 1920s and 1930s that are out of print, but still technically under copyright—meaning they’re extremely difficult to get a hold of.

The Sonny Bono Copyright Term Extension Act was a copyright extension law passed in 1998 to extend copyright protections to works published after 1923 (which would otherwise have already entered the public domain) by 20 years. Unfortunately, while Disney may be happy that Mickey Mouse still falls under copyright protections, that also means that less-famous books that are now out of print can’t be made available to the public. But a provision of the law provides for public access for research, allowing nonprofit libraries to distribute the works if they cannot be found elsewhere for a reasonable price.

Screenshot, Internet Archive

The Internet Archive explains:

We believe the works in this collection are eligible for free public access under 17 U.S.C. Section 108(h) which allows for non-profit libraries and archives to reproduce, distribute, display, and publicly perform a work if it meets the criteria of: a published work in the last 20 years of copyright, and after conducting a reasonable investigation, no commercial exploitation or copy at a reasonable price could be found.

Libraries don’t tend to take advantage of the law because it takes considerable resources to track down which works are eligible. However, the Internet Archive collaborated with Elizabeth Townsend Gard, a Tulane copyright expert, and a pair of interns to find books that could be scanned and uploaded online legally. Gard has released guidelines for libraries based on this work to help other archives do the same.

The Internet Archive is starting out with 62 books published between 1923 and 1941 (meaning they’re within 20 years of their copyright expiring) and plan to release up to 10,000 more in the near future to be downloaded and read by online users. And the collection will grow each January as more books enter that 20-year window.

[h/t Ars Technica]