@techreport{repORt:2015-028, author = {C. B\"{u}sing and S. Kirchner and A.M.C.A. Koster and A. Thome}, title = {The Budgeted Minimum Cost Flow Problem with Unit Upgrading Cost}, institution = {Lehrstuhl f\"{u}r Operations Research, RWTH Aachen University}, year = {2015}, type = {repORt}, number = {2015--028}, month = {Oct} }