You could try Sci-Hub and LibGen. If you don't find what you're looking for, you can always email the authors or other scholars who may have access to the paper you're interested in. A less alternative site would be arXiv, but it just has preprints.

sci-hub.se will get you most of papers

libgen.rs will get you most of books

Not a piracy answer, but email the author(s). Most are excited that someone is taking interest in their work and will gladly send you the paper.

I've heard you can just email one of the authors of the paper, if you're looking for a specific one.

Anna's Archive just added an academic papers feature called SciDB: https://annas-archive.org/

Scihub for most things. You can also sometimes find preprints (or contact the authors) on RG.

Sci-hub almost has everything, but you can access the rest by using a University account that pays for access

arxiv

Anna's archive has a lot of scientific papers.

sci-hub has already been mentioned, but I will say that though it is not piracy, depending on the field, you can find free version "pre-prints" of papers on arxiv.org and socarxiv.org

Also see Nexus Search (@science_nexus_bot) on Telegram.

A lot of research can be downloaded if it's open access. If it is not, you can request papers to the authors, this is really easy in platforms like ResearchGate. Others have also mentioned SciHub if you are okay with the arrr option.

https://doaj.org/

you might want to Google "Alexandra Elbakyan", for research of course 👀