ACADEMIA

I have a confession to make, I recently paid annual membership. I was repeatedly offered to me at a fee per month coming to circa £60 pa which I ignored. I was then offered it at half price (less than £30).
It has world wide coverage and links to many PhD dissertations, which you can download without joining.
The advantage of joining is that you can bulk download all related links which gives surprising prompts and they are all downloaded ready for saving or alternately you can build a library.
It is a bit of a shotgun but rewarding, I would recommend it

I can assure you she does not allow me to spend her money easily
Over recent years I have noticed that many of my more adventurous searches have pointed me to Academia and I do like the linkages given but readily agree it is not perfect.
Still,for less than £30 for a year of full access at my age is probably on a par with Leicester City winning the Premiership.