I remember finding the invaluable ADAP collection online (read only). Since I have forgotten to save bookmarks prior to a general reinstall of my laptop, I have no clue which Germany-based digital repository it was. Does anyone know?
and thank you for reminding me of the fact that IfZ has made AAPD available. But now, I am looking for the ADAP (Akten zur deutschen Aussenpolitik), series D & E (ca. 1938-45). The repository was some kind of digital library, more in the vein of archive.org...