@techreport{KosterWagler2005, author = {Arie M.C.A. Koster and Annegret Wagler}, title = {Comparing Imperfection Ratio and Imperfection Index for Graph Classes}, institution = {ZIB}, address = {Takustr. 7, 14195 Berlin}, number = {05-50}, language = {eng}, year = {2005} }