Notes, Comments and Preliminary results May 16 2004 Bertrand Crettez , Nayla Hayek and Jean-Michel Courtault   "On the differentiability of the benefit function": correction and addendum   Abstract  Contact Information  Citation  Full Text  -  Comment   Mar 24 2004 Bertrand Crettez , Naila Hayek and Jean-Michel Courtault   On the differentiability of the benefit function   Abstract  Contact Information  Citation  Full Text  -  Note