@Book{nebel2012entwurf,
  author = {Nebel, Markus},
  title  = {Entwurf und Analyse von Algorithmen},

  year   = {2012},
  number = {},
  url    = {http://d-nb.info/1018322566/04},

  const  = {\ text}
}
@Book{goodrich2011structures,
  author = {Goodrich, Michael T. and Tamassia, Roberto},
  title  = {Data structures and algorithms in Java},

  year   = {2011},
  number = {},
  url    = {http://scans.hebis.de/HEBCGI/show.pl?22309560_toc.pdf},

  const  = {\ text}
}
@Article{astrachan2003bubble,
  author = {Astrachan, O.},
  title  = {Bubble Sort: An Archaeological Algorithmic Analysis},
  journal = {SIGCSE BULLETIN},
  year   = {2003},
  number = {PART 1},
  url    = {},

  const  = {\ text}
}