CORE Discovery is the largest collection of Open Archive papers and it helps users find freely accessible copies of research papers that might be behind a paywall on the publisher’s website. It harvests research papers from data providers from all over the world including institutional and subject repositories, open access and hybrid journal publishers.
CORE currently contains *135,539,113* open access articles, from over tens of thousands of journals, collected from 9,646 data providers around the world. https://core.ac.uk/
Google Scholar is a freely accessible web search engine that indexes the full text or metadata of scholarly literature across an array of publishing formats and disciplines. Please click here www.scholar.google.co.in