CyberLeninka – CyberLeninka is a scientific electronic library.
BASE Bielefeld Academic Search Engine – One of the world’s most voluminous search engines especially for academic web resources. BASE provides more than 240 million documents from more than 8,000 content providers. You can access the full texts of about 60% of the indexed documents for free (Open Access). BASE is operated by Bielefeld University Library.
CiteSeerX – CiteSeerX is an evolving scientific literature digital library and public search engine primarily in the fields of computer and information science.
disserCat – DisserCat is a scientific electronic library for dissertations and abstracts.
eagle-i – A resource discovery tool built to facilitate translational science research. Groundbreaking biomedical research requires access to cutting edge scientific resources, but those resources are often invisible beyond the laboratories or universities where they were developed. Using eagle-i’s free software, you can collect and share information about your research resources, giving any scientist, anywhere, access to one of the largest collections of information about Core Facilities, iPS cell lines, and other valuable, unique or rare scientific resources in the world.
eLIBRARY.RU – The Russia’s largest electronic library of scientific publications and academic papers with a wide choice of search options and filters.
FreeFullPDF.com – The aim of FreeFullPDF.com is to increase the visibility and ease of use of open access scientific journals, theses, posters and patents. All scientific subjects are covered and all content are freely available in PDF format.
JournalMap – JournalMap is a scientific literature search engine that empowers you to find relevant research based on location and biophysical variables as well as traditional keyword searches.
Mednar – A free, medically-focused deep web search engine.
Mendeley – Mendeley is a reference manager and academic social network which is used to manage and share research papers and generate bibliographies for scholarly articles.
NCBI – The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information.
RefSeek – RefSeek is a web search engine for students and researchers that aims to make academic information easily accessible to everyone.
Science.gov – Science.gov is a gateway to U.S. government science information. The portal offers free access to research and development (R&D) results and scientific and technical information from scientific organizations across 13 federal agencies.
ScienceResearch.com – ScienceResearch.com is a scientific search engine.
Scopus – Scopus is the largest abstract and citation database of peer-reviewed literature: scientific journals, books and conference proceedings.
Semantic Scholar – Semantic Scholar is an artificial-intelligence backed search engine for academic publications.
Trove – Search Trove to explore amazing collections from Australian libraries, universities, museums, galleries and archives. It’s free and available online all day, every day.
WorldWideScience.org – WorldWideScience.org is a global science gateway comprised of national and international scientific databases and portals accelerating scientific discovery and progress.