I am not a lawyer, so this is not legal advice.
I think the correct way would be to include a LICENSE.txt file in each subdirectory of the individual datasets with '"<dataset title>" <link to dataset> by <author> <link to author> licensed under <license> <link to license text>' and any additional attribution instructions mentioned by the author(s), e.g. BibTeX citation instructions or additional links to institutions, web profiles, etc. The authors should be referred to by their preferred name instead of their full name if they wish so. This assumes that the entire subdirectories belong to the same author. If individual images are by different authors, things might be more complicated.
https://wiki.creativecommons.org/wiki/best_practices_for_att...
All these little details might sound petty, but there have been many lawsuits in Germany where photographers uploaded images under some creative commons attribution license and then later sued people for using their images if they forgot to include the title in their attribution. Thankfully, those lawsuits have mostly died down, but it is probably better to be safe than sorry.