https://datenrepository.baw.de/datenkataloge;jsessionid=8CF4440EA9E9BE8CC293B565B45800F8
BAW - Complete list of searchable data catalogues
You can view a full list of connected waterways data catalogues and corresponding metadata
complete listdata cataloguesbawsearchable
https://fis.uni-bamberg.de/entities/publication/0806df93-71db-4e42-b759-73f54e6bf8dd
The Text+ Registry : Federating Research Data Catalogues for the Digital Humanities
the textresearch datadigital humanitiesregistrycatalogues