@techreport{BurgerKloseSchaedleetal.2003, author = {Sven Burger and Roland Klose and Achim Sch{\"a}dle and Lin Zschiedrich}, title = {HelmPole - A finite element solver for scattering problems on unbounded domains: Implementation based on PML}, institution = {ZIB}, address = {Takustr. 7, 14195 Berlin}, number = {03-38}, language = {eng}, year = {2003} }