@techreport{BleyGroetschelWessaely1998, author = {Andreas Bley and Martin Gr{\"o}tschel and Roland Wess{\"a}ly}, title = {Design of Broadband Virtual Private Networks: Model and Heuristics for the B-WiN}, institution = {ZIB}, address = {Takustr. 7, 14195 Berlin}, number = {SC-98-13}, language = {eng}, year = {1998} }