Check DOI/PMID on webpages for https://redactek.com
nabor.mendonca
https://clickandread.inist.fr/
http://www.cocites.com/
http://pubpeer.com/
https://openaccessbutton.org
maayanlabapps
ktunya
https://oahelper.org
https://scite.ai
http://lazyscholar.org/
GetFTR
Digital Science