What is Gray Literature?
Why is Gray Literature important?
How do I find Gray Literature?
What if I cannot find what I am looking for?

What is gray literature?
Gray Literature or "Grey Literature" is literature (often of a scientific or technical nature) that is not available through the usual bibliographic sources such as databases or indexes.  It can be both in print and, increasingly, electronic formats.  

Technical reports Pre-Prints Fact Sheets Standards Patents Working papers Committee reports Business documents

Newsletters Government documents Technical documentation (e.g., space shuttle) Conference proceedings White papers Symposia Bulletins Unpublished works

Gray literature is produced by government agencies, universities, corporations, research centers, associations and societies, and professional organizations. 

Why is gray literature important?

Gray literature is an important source of information. Though not scholarly, it is produced by researchers and practitioners in the field.  It can often be produced more quickly, have greater flexibility, and be more detailed than other types of literature. "Gray literature serves scholars and lay readers alike with research summaries, facts, statistics, and other data that offer a more comprehensive view of the topic of interest (Weintraub)." 

In the future, gray literature will be even more important. "In a world in which free trade and instantaneous communication have eliminated many of the barriers to information flow, grey literature is gaining greater importance as a source of information for much of the world's population (Weintraub)."

For more information about gray literature, try IL Toolkit-Finding Information: Gray literature or The role of gray literature in the Sciences by Professor Irwin Weintraub.

How do I find gray literature?

Gray literature, due to its diverse origins and unpublished nature, can be difficult to find.  Gray literature is often found by searching for the agency or institution who is most likely to produce the literature.  The search may require looking at a large number of sources. The World Wide Web has made the dissemination of gray literature easier and advances will continue in the future.

Here are a few places to start looking for gray literature:

• Search the Gray Literature gateways listed below.
• Search the corporation, institution, or agency that is most likely to produce the type of information you are looking for.
• Search a number of scientific and general search engines using keywords.
• Search library catalogs at large scientific institutions or Worldcat.
• Consult with a librarian.

Gray Literature Gateways  (** = Highly recommended)

**DOE's Scientific and Technical INFORMATION BRIDGE (http://www.osti.gov/bridge/)
"Full-text documents produced and made available by the Department of Energy National Laboratories and grantees from 1995" to date.   Select Easy Search or Advanced Search.

**lanl.arXiv.org ePrint archive (http://xxx.lanl.gov/)
This is a huge "e-print service in the fields of physics, mathematics, non-linear science, computer science and quantitative biology maintained by Cornell University."

**Networked Computer Science Technical Reference Library (http://www.ncstrl.org/)
NCSTRL is a database of full-text computer science technical reports, mostly from universities, and also from some research centers.

**Virtual Technical Reports Center (http://www.lib.umd.edu/ENGIN/TechReports/Virtual-TechReports.html)
A good place to start if you are looking for preprints and technical reports from around the world, by institution.  This site lists hundreds of gray literature producing agencies.

**OAIster (http://www.oaister.org/)
OIAster's goal is to "create a collection of freely available, difficult-to-access, academically-oriented digital resources that are easily searchable by anyone." Includes over 3,000,000 records from 327 institutions.

Hewlett Packard Laboratories Technical Reports (http://www.hpl.hp.com/techreports/)
This site has HP Labs technical reports from 1990 to the present.  Topics include computer science, communication networks, and applied mathematics.

Jet Propulsion Laboratory Technical Report Server (http://trs-new.jpl.nasa.gov/dspace/)
JPL is the chief NASA center dedicated to planning, creating, and running unmanned space mission for the purpose of exploring the solar system.

NTRS: NASA Technical Reports Server (http://ntrs.nasa.gov/)
This server provides access to abstracts and citations of unclassified NASA technical reports, as well as NACA (NASA's predecessor) technical reports, arXiv Physics Eprint Server, BioMed Central, and the Energy Citation Database (OSTI).  Also included is some open (i.e., non-gray) literature.

Energy Technology Data Exchange (https://www.etde.org/etdeweb/logon.jsp)
Get the latest energy-related research from this site. Registration (free) is required.  "Includes information on all environmental impact of energy production and use, including climate change; energy R&D; energy policy; nuclear, coal, hydrocarbon and renewable energy technologies and more." Search 3,3500,000 records and 160,000 full text documents.

Scientific and Technical Information Network (http://stinet.dtic.mil/str/guided-tr.html)
Use to search the public file for technical reports, from 1974 to the present. This will retrieve unclassified technical reports of interest to the defense community, from various sources.  Some reports have full text online.

New York Academy of Medicine: Grey Literature (http://www.nyam.org/library/pages/what_is_grey_literature)
Use to find medical and health science related grey literature.  Website includes a list of Grey Literature Producing Organizations and a quarterly Grey Literature Report with new resources.

Agricultural Online Access (Agricola) (http://agricola.nal.usda.gov/)
"This database administrated by the National Agricultural Library and provides access to records of articles, chapters, reports, and reprints, encompassing all aspects of agriculture and allied disciplines."

US Army Corps of Engineers, Publications (http://www.usace.army.mil/publications/)
"The only repository for all official USACE engineering regulations, circulars, manuals, and other documents."

What if I cannot find what I am looking for?

Email or set up an appointment with the Science and Engineering Librarian.