http://home.planet.nl/~albert.goudriaan

http://www.physclips.unsw.edu.au/jw/sailing.html

http://i.treehugger.com/images/2007-2-21/Windmill-Sailboat.jpg

http://blog.modernmechanix.com/2007/11/27/wind-propeller-sails-proposed-for-liners

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