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Grey Literature in Transportation Topics
Much of the literature that you will find on transportation is grey literature. The term grey literature refers to literature that is not commercially published. Rather, it is published by non-profits, research agencies, governments, etc. TRID, the main database for transportation, includes many citations to grey literature, but it can be helpful to supplement your searches by looking at institutional and agency web sites, and by searching databases containing citations to working papers.
Grey Literature Resources
Index to Current Urban Documents
Contains reports generated by local government agencies, civic organizations, and metropolitan and regional planning agencies for major cities in the United States and Canada.
Bielefeld Academic Search Engine (BASE)
BASE is one of the world's most voluminous search engines especially for academic open access web resources. BASE is operated by Bielefeld University Library.
System for Information on Grey Literature in Europe, is your open access to 700.000 bibliographical references of grey literature (paper) produced in Europe and allows you to export records and locate the documents.
Social Sciences Research Network (SSRN)
Features academic networks for many disciplines in the social sciences. Includes a database with abstracts of scholarly working papers and forthcoming papers. Also includes a paper collection of full-text documents.
What is Grey Literature?
Watch this two-minute video for a brief introduction to grey literature from Western University.