Photo Attribution
Wikipedia user: Towpilot
Creative Commons Attribution-Share Alike 3.0 Unported
Luca Sartoni
Creative Commons Attribution-ShareAlike 2.0 Generic (CC BY-SA 2.0)
Gage Skidmore
Creative Commons Attribution-Share Alike 3.0 Unported
Georges Biard
Creative Commons Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0)
Dick Thomas Johnson
Creative Commons Attribution 2.0 Generic (CC BY 2.0)
gdcgraphics
Creative Commons Attribution 2.0 Generic (CC BY 2.0)