Pirate Scientific Articles

Libgen/Scihub

• https://libgen.is
  
• https://libgen.fun
  
• https://libgen.rs
  
• https://libgen.io

Z-lib

• https://z-lib.org
• https://b-ok.cc (a subwebsite form z-lib)

Standard Template Construct

• https://standard--template--construct-org.ipns.dweb.link/#/

PDF Drive

• https://pdfdrive.com

Telegram Bots

• NexusSearch @nexussearchanotherbot (https://t.me/nexus_search_another_bot)
• Nexus Search @sciencenexusbot (https://t.me/science_nexus_bot)
• Sci-Hub @scihubot (https://t.me/scihubot)

Twitter

• post a request with the hashtag #ICanHazPDF

Reddit

• r/scholar (follow the rules)

Other

• Request on Researchgate or email the authors.
• Check with the librarian at your college. They're usually happy to help with this sort of thing and will use legitimate channels to get your articles via interlibrary loan.