A Good Time to Learn More About Poland/Ukraine History

Having recently finished Ruta Sepetys' Salt to Sea, this seems like an excellent follow-up novel. I never knew how much Poland was being squeezed by both sides of the war....Germany & Russia/Ukraine. I am eager for stories relating to this geographical region, what with all that is going on in Ukraine right now. Reading historical fiction like this makes the history much more relatable than reading a non-fiction history book.