Andrea Asperti Herman Geuvers Iris Loeb Lionel Elie Mamane Claudio Sacerdoti Coen An Interactive Algebra Course with Formalised Proofs and Definitions. 315-329 2005 conf/mkm/2005 MKM http://dx.doi.org/10.1007/11618027_21 db/conf/mkm/mkm2005.html#AspertiGLMC05