@techreport{WaKlW08b,
  address = {Universit\"at Kassel},
  author = {Wagner, R. and Klaus, M.},
  institution = {DMCC - Dialog Marketing Competence Center},
  interhash = {ad8d44fc046760b61ca60011d7a1a714},
  intrahash = {826dba13e4bcb6973db0564882100455},
  number = 2,
  title = {{C}hallenges and {E}xamples of {M}obile {D}irect {M}arketing},
  type = {Dahlhoff, D. and Mann, A. and Wagner, R.},
  year = 2008
}

@incollection{WaKlC08b,
  address = {Hershey},
  author = {Wagner, R. and Klaus, M.},
  booktitle = {{H}andbook of {R}esearch on {M}obile {B}usiness},
  edition = 2,
  editor = {Unhelkar, B.},
  interhash = {05ea12af2cb7db5a1815da75bc90521a},
  intrahash = {8a99471d5836acaee96776dd79469d31},
  pages = {269 - 281},
  publisher = {{I}{G}{I}},
  title = {{M}obile {D}irect {M}arketing},
  url = {http://books.google.de/books?hl=de&lr=&id=JlpFnu8hMK4C&oi=fnd&pg=PA269&dq=martin+klaus+%22ralf+Wagner%22&ots=GXB0O_sNC_&sig=Jdr05yCvx_U5h4YlXX9EGVWOioU#PPA269,M1},
  year = 2008
}