A scientific portal and social network for scientists, a means of collaboration between scientists from any scientific discipline, containing web applications, including semantic search, file sharing, sharing of the publication database, forums, methodological discussions, groups, etc. Among other tools, ResearchGate has developed a semantic search engine that searches internal resources and major external databases such as PubMed, CiteSeer, arXiv, the NASA Library, etc., to find scientific articles.
You can check the indexation on the website:
https://www.researchgate.net/