@book{9783865960672,
  title = {Ravenna},
  author = {Wilhelm Schmidt},
  publisher = {Frank \& Timme},
  year = {2009},
  edition = {1},
  series = {Theologie/Religionswissenschaft},
  volume = {6},
  url = {https://www.frank-timme.de/en/programme/product/ravenna-die\_botschaft\_seiner\_bilder}
}