General References
HighWire Press

HighWire Press

HighWire Press is the largest archive of free full-text science on Earth! As of 2/4/15, we are assisting in the online publication of 2,546,441 free full-text articles and 7,668,694 total articles. There are 50 sites with free trial periods, and 118 completely free sites. 292 sites have free back issues, and 1374 sites have pay per view!

The World Bank DataBank

The World Bank DataBank

DataBank is an analysis and visualisation tool that contains collections of time series data on a variety of topics. You can create your own queries; generate tables, charts, and maps; and easily save, embed, and share them.