Normally that's the case even though at least one of those books was taken down based on (rather dubious imo) violation of rights on derivative works. It was never a verbatim rewrite nor a trademark violation. The Dutch court even proceeded to make a list of similar ideas between two books which I think is explicitly disallowed under the US version of the copyright law.

https://en.m.wikipedia.org/wiki/Tanya_Grotter

( Not only that, even what they say it's russian culture and folklore, it's based on polish history and tales: https://en.m.wikipedia.org/wiki/Łysa_Góra )