The Polish Wikipedia page of W W Sawyer lists titles of the translations (with some publication details) of his books into Polish, but not the original titles (Mathematicians' Delight seems to be Matematyka Nauka Przyjemna; I don't have a copy at hand to confirm). Some of these translations had multiple editions; covers can be seen here: https://www.google.com/search?source=univ&tbm=isch&q=W+W+Sawyer+matematyka&client=firefox-b&sa=X&ved=2ahUKEwiDscvv7PXpAhUS2qwKHdOLBe8QsAR6BAgIEAE&biw=1588&bih=713