The Samuelson Clinic has released Is It in the Public Domain?.
Here's an excerpt from the announcement:
Here's an excerpt:
The handbook walks readers though a series of questions—illustrated by accompanying charts—to help readers explore whether a copyrighted work from that time is in the public domain, and therefore free to be used without permission from a copyright owner. Knowing whether a work is in the public domain or protected by copyright is an important first step in any decision regarding whether or how to make use of a work.