@techreport{FrieseSchmidtYevick1999, author = {Tilman Friese and Frank Schmidt and David Yevick}, title = {Transparent Boundary Conditions for a Wide-Angle Approximation of the One-Way Helmholtz Equation}, institution = {ZIB}, address = {Takustr. 7, 14195 Berlin}, number = {SC-99-45}, language = {eng}, year = {1999} }