Jean-Paul Doignon Samuel Fiorini Facets of the Weak Order Polytope Derived from the Induced Partition Projection. 112-121 2001 15 SIAM J. Discrete Math. 1 http://epubs.siam.org/sam-bin/dbq/article/36993 db/journals/siamdm/siamdm15.html#DoignonF01