@incollection{Czychowski2023,
  author    = {Christian Czychowski},
  title     = {\S 31 Angemeldete Marken},
  booktitle = {Markengesetz},
  edition   = {4., neu bearbeitet},
  editor    = {Axel Nordemann and Anke Nordemann-Schiffel},
  isbn      = {978-3-406-75086-1},
  url       = {https://beck-online.beck.de/Bcid/Y-400-W-IngerlRohnkeMarkenGKO-G-MarkenG-P-31},
  year      = {2023},
}