@book{MulthaupSchengber2003,
  author    = {Multhaup, Roland and Schengber, Ralf},
  title     = {Internetauftritte deutscher St{\"a}dte},
  volume    = {31},
  edition   = {1. Aufl.},
  publisher = {Fachhochsch.},
  address   = {M{\"u}nster},
  pages     = {58 Bl. : Ill., graph. Darst.},
  year      = {2003},
  language  = {de}
}
@book{Schengber2006,
  author    = {Schengber, Ralf},
  title     = {Werbung und Product Placement in Computerspielen},
  address   = {M{\"u}nster},
  year      = {2006},
  language  = {de}
}
@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}
}
@book{Schengber2005,
  author    = {Schengber, Ralf},
  title     = {Erfahrungen und Erwartungen an Mobile Marketing - Eine vergleichende Studie von Konsumenten, Unternehmen und Experten},
  year      = {2005},
  language  = {de}
}