@incollection{Harden2015,
  author    = {Lars Harden},
  title     = {Keyword: Wirkungsforschung},
  series = {Methoden-Lexikon f{\"u}r die Sozialwissenschaft},
  publisher = {Springer VS},
  address   = {Wiesbaden},
  pages     = {437},
  year      = {2015},
  language  = {de}
}