WEB OF GREY
Turning to websites with a scientific or technical focus that contain a significant amount of grey literature content, these databases emanate mainly from the government or academia. Most of these resources also have journal articles and sometimes book citations as well.
Agricola (agricola.nal.usda.gov) is the major database from the U.S. Department of Agriculture (USDA). The public version of the database also serves as the national catalog for the USDA library. A number of vendors offer a version of the database with a much more user-friendly interface. Before you starting searching the public version of Agricola, I suggest looking at the NAL Catalog (Agricola): Common questions page (agricola.nal.usda.gov/help/faq.html). Although it is not my favorite resource, it does contain sci/tech grey literature such as cooperative extension reports not found elsewhere.
Defense Technical Information Center (DTIC) (dtic.mil/dtic) is a searchable repository for supposedly all publicly available Department of Defense (DOD) scientific and technical research. In truth, probably only some of them are found here. Still, DOD funds research on an incredible array of scientific and technical from nanotechnology to human performance, and almost all the material is grey literature. The main interface offers a variety of search options; my recommendation is to choose the advanced search and under the All Collections menu, click on Technical Reports as a starting point.
ENTEWEB World Energy Base (etde.org/etdeweb/fieldedsearch.jsp?pg=3) is an international database covering all aspects of energy research. It is operated by the International Energy Administration (IEA) in conjunction with energy agencies from host countries—in the United States, this is the DOE. The advanced search interface is fairly intuitive. The Resource/Doc Type search field allows you to limit your results to grey literature sources. The database is a great resource for energy-related international resources.
IAEA’s INIS Database (iaea.org/inis), produced by the International Atomic Energy Administration (IAEA) in partnership with 150 country members, is one of the world’s largest collections of information covering all aspects of the peaceful uses of nuclear science and technology. The database contains a number of journal articles. To bypass these and concentrate on the grey literature, use advanced search. Under the “but do not include” search option, choose journal. [For more information on INIS, see “Nuclear Information Democratization” by Dobrica Savic, in the November/December 2013 issue of Online Searcher. —Ed.]
National Technical Information Service (NTIS; ntis.gov) acts as the primary repository for all unclassified reports from the U.S. government and assorted international government agencies. The database contains more than 2 million records, although the majority of U.S government documents do not find their way to NTIS. The public interface for NTIS is not user-friendly; a number of vendors offer much more intuitive and effective search options. Use the advanced search. One good aspect of NTIS is that more than 90% of its content is grey literature, and this does include many science and technical resources.
NASA Technical Reports Server (nix.nasa.gov/search.jsp) is the repository for all research funded by the NASA. With the highly decentralized nature of NASA, it is hard to know how comprehensive the resource truly is. NASA does research on a surprisingly broad range of scientific and technical subjects. The database does contain a number of journal articles. The best way to eliminate these from your search is to use the advanced search, click on document type list, and make the appropriate selections.
ASTROPHYSICS AND GEOLOGY
SAO/ NASA Astrophysics Data System (ADS; adsabs.harvard.edu/index.html) is funded by NASA and operated by the Smithsonian Astrophysical Observatory (SAO). It consists of three different bibliographic databases—Astronomy and Astrophysics, Physics, and arXiv eprints. The search interface is perhaps the most daunting of all the resources that I’ve covered. It is not intuitive but can return very powerful results. The Astronomy and Astrophysics and the Physics databases contain a very high number of journal articles but are also excellent sources for conference papers and proceedings.
The U.S. Geological Service Publications Warehouse (pubs.er.usgs.gov) serves as a database for publications written by USGS scientists. It contains more than 100,000 citations, with links to the actual publications. A large number of these publications are journal articles, but many grey literature resources can be found here. The search interface is very nice—user-friendly and intuitive. One suggestion: Under the Limit By menu, choose publication type, then click on the carat on the right-hand side to select the specific format you want.
ACADEMIC RESEARCH DATABASES
arXiv (arxiv.org), maintained by Cornell University, is one of the oldest and largest eprint (pre-print) resources in the world. It provides open access to more than 900,000 eprints in the areas of physics, mathematics, computer science, quantitative biology, and quantitative statistics. As is the case with almost all these resources, the advanced search is always a good choice. Many of the items found in arXiv, but not all, are published as research articles in conventional print and ejournals as well.
CiteSeerX (citeseer.ist.psu.edu) is a digital library and search engine focused on computer and information science that is maintained by Pennsylvania State University. The search interface can be a little complicated to figure out, but it does allow for a great deal of flexibility. It contains a significant number of journal articles but is an excellent source for conference papers and conference proceedings.
INSPIRE-HEP (inspirehep.net) is a database for the high energy, particle physics, and astrophysics fields. It was developed and is maintained by a collaboration of research labs and publishers working in the area of high energy physics. The interface looks somewhat funky but provides a good number of search options. The database contains a large number of journal articles but is an excellent resource in particular for conference papers and proceedings.
It is also important to remember that dozens of open access technical and scientific databases with primarily grey information are also available. Because they may be less well-known and more specialized or technical in nature, these databases do not get as much attention. Science librarians have created some excellent guides for these resources. One example is the listing of open access databases in geology and marine sciences from the University of New Orleans library (libguides.uno.edu/content.php?pid=161121&sid=1400581).
FUTURE OF GREY LIT
What does the future holds for scientific and technical grey literature resources? I think that these resources will continue to play a major role. Three trends will impact exactly how a big that role will be.
Increasing quantity. The ease of self-publishing and rise of web-only documents will only continue to increase the amount of sci/tech grey literature. My biggest concern is that the increasing number of reports may result in a decrease of the quality and reliability of the information.
More collaboration. The time is probably not far off when we will see sci/tech grey literature reports that will be edited by teams of scientists, engineers, and other experts in real time.
The problems with finding sci/tech grey literature resources will start to be addressed. I suspect that many of the science publishing vendors and aggregators and perhaps a few government agencies are working on this issue right now. However, these organizations will not get serious about solving these problems until they can see the financial benefit of doing so.