SciSpace is a scholarly search engine for math and science. Watch the video to see what it can do.
Add the pdf or url to an article you like. Creates a map of related articles you can sort by "prior works" -- previous articles that were seminal to the article you submitted -- or "subsequent works" -- articles that came later and may have developed the topic further. Helps understand the academic conversation around your topic. Free account allows 5 graphics/month.
Elicit
Powerful scholarly search engine. Search for articles by methodology, limitations, participants, and much more.
Ask for your topic to find relevant books. Also great to find a good fiction read!
Drop in any PDF and start talking -- have it summarize, list main ideas, and more!
Note that this presentation has been updated so not all screens are the same, but there are many useful tips on how to search Gale and EBSCO..
If you find an article that is not available in full-text, best bet is to paste the full title (with quotations) into Google Scholar. If that doesn't help, you can try some of the "Paywall Unlocking" tools in the box below.
Email your librarian if you get really stuck!
Open Source Databases:
Long list of Open Source databases, via Mercyhurst University
A Chrome extension to help access articles behind a paywall
Not a search engine, but a mega-site of open-source information
Open Access Button - another extension/service to unlock articles behind a paywall