@book{LinssenMarksMeyer2005,
  author    = {Linssen, R. and Marks, E. and Meyer, A.},
  title     = {Quality in Crime Prevention},
  address   = {Norderstedt},
  isbn      = {3-8334-4194-1},
  pages     = {220 S},
  year      = {2005},
  language  = {de}
}
@incollection{LinssenMarks2009,
  author    = {Linssen, R. and Marks, E.},
  title     = {School shootings - Considerations on prevention subject to relative ignorance of the phenomenon},
  series = {Coester, M. \& Marks, E. (Hrsg.), International Perspectives of Crime Prevention 2. Contributions from the 2nd Annual International Forum 2008},
  booktitle = {Coester, M. \& Marks, E. (Hrsg.), International Perspectives of Crime Prevention 2. Contributions from the 2nd Annual International Forum 2008},
  edition   = {1.Aufl},
  publisher = {Forum Verlag Godesberg},
  address   = {M{\"o}nchengladbach},
  isbn      = {978-3-936999-},
  pages     = {89 -- 98},
  year      = {2009},
  language  = {en}
}
@article{LinssenMarks2009,
  author    = {Linssen, R. and Marks, E.},
  title     = {Amokl{\"a}ufe an Schulen -Pr{\"a}ventions{\"u}berlegungen unter den Bedingungen relativen Nichtwissens},
  series = {Forum Kriminalpr{\"a}vention, 9. Jg.},
  journal   = {Forum Kriminalpr{\"a}vention, 9. Jg.},
  number    = {4},
  year      = {2009},
  language  = {mul}
}