@Incollection{michael2007bibliographie,
  author = {Rathmann, Michael},
  title  = {Bibliographie},

  year   = {2007},
  number = {},
  url    = {},

  const  = {\ text}
}
@Incollection{michael2007einleitung,
  author = {Rathmann, Michael},
  title  = {Einleitung},

  year   = {2007},
  number = {},
  url    = {},

  const  = {\ text}
}