Andrei Popescu Elsa L. Gunter Christopher J. Osborn Strong Normalization for System F by HOAS on Top of FOAS. 31-40 2010 LICS http://doi.ieeecomputersociety.org/10.1109/LICS.2010.48 conf/lics/2010 db/conf/lics/lics2010.html#PopescuGO10