Possibly Not Closed Convex Polyhedra and the Parma Polyhedra Library. - Roberto Bagnara; Elisa Ricci 002; Enea Zaffanella; Patricia M. Hill (SAS, 2002)

Precise widening operators for convex polyhedra. - Roberto Bagnara; Patricia M. Hill; Elisa Ricci 002; Enea Zaffanella (Sci. Comput. Program., 2005)