A while back I wanted to use a story by Edgar Rice Burroughs in my radio stream. The story in question I assumed to be public domain in 70+ countries, like Norway, where I was residing at the time. However, when I contacted the Edgar Rice Burroughs literary estate they told me it was not due to some Bern agreement or something, which they said extended US copyrights (95+) into Norway. When I contacted a Norwegian legal scholar in order to have this verified, he told me this was not the case. I did not use the story because I know that some literary estates try to intimidate those with fewer financial resources. Nor was I short of alternatives of equal quality. My question is: what are the facts? Do certain trade agreements extend US copyrights into another country, and vice versa?