@techreport{KokottLoebel1996, author = {Andreas Kokott and Andreas L{\"o}bel}, title = {Lagrangean Relaxations and Subgradient Methods for Multiple-Depot Vehicle Scheduling Problems}, institution = {ZIB}, address = {Takustr. 7, 14195 Berlin}, number = {SC-96-22}, language = {eng}, year = {1996} }