@incollection{SchwinnVorderwuelbecke2016,
  author    = {Horst Schwinn and Klaus Vorderw{\"u}lbecke},
  title     = {Das grammatische Lernsystem ProGr@mm},
  series = {Linguistik lernen im Internet. Das Lehr-/Lernportal PortaLingua},
  editor    = {Ulrich Schmitz},
  publisher = {Narr},
  address   = {T{\"u}bingen},
  isbn      = {3-8233-6073-6},
  url       = {https://nbn-resolving.org/urn:nbn:de:bsz:mh39-50896},
  pages     = {87 -- 100},
  year      = {2016},
  language  = {de}
}