Started in August 1991, arXiv.org is the premier electronic archive and preprint distribution server for research material in physics and astronomy. Significant material from mathematics, computer science, nonlinear sciences, quantitative biology, and statistics is also included.. Searching can be done by title, abstract, authors, keywords across the entire record, and a number of other fields. There is also an experimental full-text search of the entire document text.

The U.S. Department of Energy's Information Bridge database provides access to the full text of over 27,000 DOE research and development reports in the sciences with multidisciplinary coverage of environmental and energy sciences including the fields of physics, chemistry, materials, biology, environmental science, energy technologies, engineering, computer and information science, renewable energy, and other topics. Leads to citations plus full-text for unclassified DOE reports.