@Book{pittman2009,
  author = {Pittman, Gregory and Schäfer, Christoph},
  title  = {Scribus: open source desktop publishing. The official manual},

  year   = {2009},
  number = {},
  url    = {http://www.worldcat.org/search?qt=worldcat_org_all&q=9780956078001},

  const  = {\ text}
}
@Book{priemer2007,
  author = {Priemer, Markus},
  title  = {Scribus kompakt},

  year   = {2007},
  number = {},
  url    = {http://opac.bibliothek.uni-kassel.de/DB=1/PPN?PPN=195707613},

  const  = {\ text}
}