@article{GottschlichDrenckhahn2005,
  author    = {G{\"u}nter Gottschlich and Detlev Drenckhahn},
  title     = {Iconography of the Genus Hieracium in central Europe - Part 1: General Description and Morphotypes},
  doi       = {10.3264/FG.2005.0502},
  year      = {2005},
}