Rasmus Lerchedahl Petersen Lars Birkedal Aleksandar Nanevski Greg Morrisett A Realizability Model for Impredicative Hoare Type Theory. 337-352 2008 ESOP http://dx.doi.org/10.1007/978-3-540-78739-6_26 conf/esop/2008 db/conf/esop/esop2008.html#PetersenBNM08