@incollection{GroetschelWakabayashi1990, author = {Martin Gr{\"o}tschel and Yoshiko Wakabayashi}, title = {Composition of facets of the clique partitioning polytope}, booktitle = {Topics in combinatorics and graph theory. Essays in honour of Gerhard Ringel}, editor = {Rainer Bodendiek and Rudolf Henn}, pages = {271 -- 284}, year = {1990}, }