arXiv.org

arXiv is an open-access archive for 1,741,837 scholarly articles in the fields of physics, mathematics, computer science, quantitative biology, quantitative finance, statistics, electrical engineering and systems science, and economics. Materials on this site are not peer-reviewed by arXiv. arXiv is founded by Paul Ginsparg in 1991 and maintained and operated by Cornell University, the Simons Foundation, member institutions, and donors.

https://arxiv.org/

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   It is a gateway to global scholarly literature including articles, theses, books, abstracts and court opinions, from academic publishers, professional societies, online repositories, universities and other web sites. 

Website: - https://scholar.google.com/