http://www.1939.pl/index.html - Poland company 1939 - OOB (part Organizacja wojsk and Bitwy i potyczki) and weapon (Uzbrojenie) with excelent drawings main models of weapon
http://derela.republika.pl/ - Polish armour (include armoured trains)
http://www.2wojna.pl/spis-pl-art.html - Polska artyleria - Polish artillery (link on Polish)