They came from the first of several writers to publish for the Stratemeyer Syndicate under this pseudonym, Leslie McFarlane. I'm sure some admin will have a fun time sorting out what to do with the catalog entry when the works of John Button, Harriet Stratemeyer Adams, or Amy McFarlane under this name become public domain in the US.InTheDesert wrote: ↑January 18th, 2023, 1:37 am Not sure if this is the right thread, but where did the birth and death dates in the catalog for a pseudonym come from?
If you're asking for the purpose of copyright outside the US, unless there's an edge case involving the fact that the real name of the writer wasn't commonly known until 49 years after the first was published, McFarlane's work isn't PD in death+50 countries until at least 2028.