ScienceDirect is described as 'provides subscription-based access to a large database of scientific and medical research. It hosts over 12 million pieces of content from 3,500 academic journals and 34,000 e-books' and is an website in the News & Books category. There are three alternatives to ScienceDirect, not only websites but also apps for Windows. The best alternative is Library Genesis, which is free. Other great sites and apps similar to ScienceDirect are Sci-Hub (Free) and Libgen Desktop (Free, Open Source).