@techreport{HelmbergRendlWeismantel1995, author = {Christoph Helmberg and Franz Rendl and Robert Weismantel}, title = {Quadratic Knapsack Relaxations Using Cutting Planes and Semidefinite Programming: extended abstract}, institution = {ZIB}, address = {Takustr. 7, 14195 Berlin}, number = {SC-95-37}, language = {eng}, year = {1995} }