I would like to, with whole pleasure, introduce new book about polish eagles by T.Zawistowski " Polish cap eagles 1914-1919". On website is also available errata (in pdf format) for second part of his book which is about eagles made in West between 1939-1945.
If you donīt know these books yet, you missed a lot! "Must have" for any polish militaria collector!
Tomasz Zawistowski - Polskie or?y do czapek 1919-1945