Google Scholar provides a simple way to broadly search for scholarly literature. From one place, you can search across many disciplines and sources: articles, theses, books, abstracts and court opinions, from academic publishers, professional societies, online repositories, universities and other web sites.
BASE
BASE is one of the world's most voluminous search engines especially for academic web resources. The index contains more than 400 million records from more than 11,000 content providers. You can access the full texts of about 60% of the indexed records for free (Open Access). BASE is operated by Bielefeld University Library.
RefSeek is a web search engine for students and researchers that aims to make academic information easily accessible to everyone. RefSeek searches more than five billion documents, including web pages, books, encyclopedias, journals, and newspapers. RefSeek's unique approach offers students comprehensive subject coverage without the information overload of a general search engine—increasing the visibility of academic information and compelling ideas that are often lost in a muddle of sponsored links and commercial results.
Cannot restrict search by date.
RePEc Research Papers in Economics
RePEc (Research Papers in Economics) is an initiative that seeks to enhance the dissemination of research in Economics and related areas.
The largest collection of on-line Economics working papers, journal articles and software.
Can do advanced searches.
Science.gov is an official website of the U.S. government providing ready access to the massive stores of federally funded scientific research results, without needing to know which agency funded the research. Research results include scientific and technical reports, peer-reviewed scholarly publications, digital data, software, conference presentations and proceedings, and other scientific and technical information that federal agencies publish resulting from their research investments.
On the results page from the initial search, one can change the date range or select the visual guide to help narrow down the search.
Bioline International is a not-for-profit scholarly publishing cooperative committed to providing open access to quality research journals published in developing countries. BI's goal of reducing the South to North knowledge gap is crucial to a global understanding of health (tropical medicine, infectious diseases, epidemiology, emerging new diseases), biodiversity, the environment, conservation and international development. By providing a platform for the distribution of peer-reviewed journals (currently from Bangladesh, Brazil, Chile, China, Colombia, Egypt, Ghana, India, Iran, Kenya, Malaysia, Nigeria, Tanzania, Turkey, Uganda and Venezuela), BI helps to reduce the global knowledge divide by making bioscience information generated in these countries available to the international research community world-wide.
Each search engine has its own method of searching and each will return different results. Dogpile looks at all of them, decides which are most relevant to your search, eliminates duplicates and reveals them to you. In the end, you get a list of results more complete than anywhere else on the Web.
No advanced search facility.