R-Uni (A List of Free R Tutorials and Resources in Universities webpages) by Pairach Piboonrungroj.
A list of eighty-seven (87) university-based resources on R.
I suspect there is a fair amount of duplication just in terms of resources cited at each of those resources.
Duplication/repetition isn’t necessarily bad, but imagine having a unique list of resources on R.
Or tagging in articles on R that link back into resources on R, in case you need a quick reminder on a function.