IDEAS is the largest bibliographic database dedicated to Economics and available freely on the Internet. Based on Research Papers in Economics (RePEc), which is a collaborative effort of hundreds of volunteers in many countries to enhance the dissemination of research in economics.

NCSTRL (pronounced "ancestral", Networked Computer Science Technical Reports Library) is an international collection of computer science technical reports made available for non-commercial use from a number of participating institutions.

The Scholarly Publishing and Academic Resources Coalition (SPARC) is an international alliance of academic and research libraries.

Gale is an American educational publishing company based in Farmington Hills, Michigan, west of Detroit. It has been a division of Cengage since 2007.

Scirus is a search engine that scans an international collection of institutional repositories and other resources.

ICPSR, the Inter-university Consortium for Political and Social Research, was established by University of Michigan in 1962, an integral part of the infrastructure of social science research.

the most comprehensive source of global decision-making data in the world

Worldometer is run by an international team of developers, researchers, and volunteers with the goal of making world statistics available in a thought-provoking and time relevant format to a wide audience around the world.

EPA National Publications