@incollection{Sperlbaum1982,
  author    = {Sperlbaum, Margret},
  title     = {Zur Hochlautung der Frikative in der deutschen Regelsprache. Bericht {\"u}ber eine empirische Untersuchung},
  series = {Zur gesprochenen deutschen Umgangssprache I},
  editor    = {Bresson, Daniel and Sperlbaum, Margret and Richter, Helmut and Knetschke, Edeltraud and Droescher, Werner O.},
  publisher = {Niemeyer},
  address   = {T{\"u}bingen},
  isbn      = {3-484-23029-0},
  url       = {http://nbn-resolving.de/urn:nbn:de:bsz:mh39-82625},
  series    = {Phonai, Deutsche Reihe, Beihefte},
  number    = {5},
  pages     = {33 -- 77},
  year      = {1982},
  language  = {de}
}
@incollection{Sperlbaum1974,
  author    = {Sperlbaum, Margret},
  title     = {Isoglossenvergleich auf Grund indirekter und direkter Spracherhebung},
  series = {Spezielle methodische Untersuchungen sprachlicher Ph{\"a}nomene. Festschrift f{\"u}r Eberhard Zwirner, Teil III},
  editor    = {Richter, Helmut and Rensch, Karl H. and Sperlbaum, Margret and Knetschke, Edeltraud},
  publisher = {Niemeyer},
  address   = {T{\"u}bingen},
  isbn      = {3-484-23014-2},
  url       = {http://nbn-resolving.de/urn:nbn:de:bsz:mh39-82213},
  series    = {Phonai, Deutsche Reihe, Beihefte},
  number    = {2},
  pages     = {75 -- 88},
  year      = {1974},
  language  = {de}
}