@book{Keller2023,
author = {Keller, Gottfried},
year = {2023},
language = {ger},
copyright = {https://creativecommons.org/public-domain/cc0/},
title = {Cypripedilum, Ophrys, Serapias, Aceras, Himantoglossum, Barlia, Anacomptis, Neotinea, Steveniella. 3. Band},
url = "http://dx.doi.org/10.17169/refubium-39069",
}