@article{Dittler,
  author    = {Ullrich Dittler},
  title     = {Widefield-Refraktor f{\"u}r Einsteiger: Das Bresser Messier AR-102s im Test},
  series = {Abenteuer Astronomie},
  number    = {Extra 1/2017: Teleskope und Ferngl{\"a}ser},
  issn      = {2366-3944},
  pages     = {52 -- 55},
  language  = {de}
}