Stirling Nasa

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19830022057_1983022057.pdf

http://www.amazon.com/Stirling-Engine-Design-William-Martini/dp/1410216047/ref=sr_1_1?ie=UTF8&s=books&qid=1264781707&sr=1-1