Links to useful FREE library sites

Google Scholar: https://scholar.google.com/. Probably the best way to access recent scientific literature on the internet. 

Biodiversity Heritage Library: http://www.biodiversitylibrary.org/. A remarkable free online source of biodiversity publications that are out of copyright and many (e.g., KU series) that are still in copyright. I use this site almost daily. See https://en.wikipedia.org/wiki/Biodiversity_Heritage_Library.

Internet Archive: https://archive.org/. Another remarkable free online source of publications. See https://en.wikipedia.org/wiki/Internet_Archive. I rarely start looking with this website, but I frequently end up here.