Map of warsaw tramway network, before destruction of network in 1945
http://sharemap.org/public/Warsaw_streetcar_network_before_1939
Geospatial data sources: 

http://wiki.openstreetmap.org/wiki/OpenStreetMap_License - Open Street Map Data (CC-SA-BY)
http://www.trasbus.com/plan1938-2.htm - City map (pre war - public domain)
Jkan997