Use these open source databases to search for more academic sources for your research projects.
arXiv (pronounced "archive") gives you onine access to electronic pre-prints of scientific papers in the field of mathematics, physics, astronomy, computer science, quantitative biology, statistics, and quantitative finance.
bioRxiv (pronounced "bio-archive") gives you free online access to unpublished pre-prints in the life sciences.
Plos publishes a suite of influential Open-Access journals across all areas of science and medicine.