@article{Schengber2005,
  author    = {Schengber, Ralf},
  title     = {Killerapplikationen Mobile Marketing},
  series = {Marketingjournal},
  journal   = {Marketingjournal},
  year      = {2005},
  language  = {mul}
}
@book{Schengber2004,
  author    = {Schengber, Ralf},
  title     = {Handynutzungsverhalten in Deutschland - Eine Studie},
  address   = {M{\"u}nster},
  year      = {2004},
  language  = {mul}
}
@book{Schengber2005,
  author    = {Schengber, Ralf},
  title     = {Mobile Marketing - Wir sind noch ganz am Anfang},
  year      = {2005},
  language  = {mul}
}