David Roundy, Michael Rogers, Exploring the Thermodynamics of a Rubber Band, American Journal of Physics, 81, 20–23 (2013) (Copyright Notice) (pdf) (html)
Grant Sherer, Mary Bridget Kustusch, Corinne A. Manogue, and David Roundy, The Partial Derivative Machine, 2013 Physics Education Research Conference, Portland, OR (submitted).