Created with the support of the European Community, the base was produced from 1985 onwards by EAGLE - European Association for Grey Literature Exploitation. Each country is represented by one or more documentation centres or libraries of national importance.
By 2004/2005 many country members had created online archives or catalogues including grey literature. On the other hand, too much development was needed to include the increasing number of electronic documents in SIGLE. In 2005, the members of EAGLE decided on the dissolution of the association and stopping of supplying new documents. The database SIGLE has been taken off from all hosts proposing the base online and a database which is no longer updated does not interest commercial hosts such as STN International.
Institut de l\\'Information Scientifique et Technique (INIST) however thought that the main effort made by the EAGLE members was to obtain the grey documents for their collections, and that many users would still be interested to get them. About 30% of the references are in Humanities and Social sciences. According it transferred most of the references (700 000) to an open access environment, using DSpace software.
Only grey literature produced in and collected by the former member countries (all in Europe) is available. INIST has launches the OpenSIGLE project: to transfer the SIGLE database to online open access. All bibliographical references are searchable again, and henceforth free of charge, with OpenSIGLE.
"The first user statistics," says Christiane Stock Head of Monographs and Grey Literature at INIST "are showing that many visitors come from France, the UK and the USA, besides other former members, but we get also visitors from Canada, China, Romania."
Called "the unsung hero, the foot soldier, the foundation of the building" grey literature is not usually attainable through conventional channels. Easier to describe, rather than define collectively the term covers an extensive range of materials that cannot be found easily through conventional channels such as publishers, "but which is frequently original and usually recent."
Quasi-printed reports, unpublished but circulated papers, unpublished proceedings of conferences, printed programs from conferences, and the other non-unique material which seems to constitute the bulk of our modern manuscript collections . Important contributions to the genre are translations, constituting a major part of grey literature. Two reasons can easily be discerned to explain why. If half the scientific and technical literature is written in languages other than English, and if scientists from all around the world, including those from English-speaking countries want to access the research, they need translations of the work.
Dissertations also make up an important part of grey literature, as well as \\'meeting papers\\' or preprints that are given out before conferences and meetings, and could end up as journal articles."
Grey literature was for many years synonymous with \\'reports literature\\'. Documents evolving out of research and development, particularly from the aircraft and aeronautics industries were a very important means of communicating the results of research testing.
Technology push to gray literature
The hallmark of World War Two was the development of technologically-advanced weaponry, from sophisticated tanks to the atomic bomb. These breakthroughs in science made accurate and speedy communications a necessity. The technical report was widely used to disseminate information. Subsequently staggering amounts of scientific and technological research were amassed to improve both military and communication systems.
The one thing that made grey literature so attractive and "attained its importance as a separate medium of communication was because of an initial need for security or confidentiality classifications which prevent documents being published in the conventional manner."
In recent years, technical and scientific literature has continued to grow, but now grey literature reports are coming from many different avenues. According to author Charles Augur these comprise Associations, Churches, County councils, Educational establishments, Federations, Institutes, Institutions, Laboratories, Libraries, Museums, Private publishers, Research establishments, Societies Trade unions, Trusts and Universities.
By the 1970s, it was a recognised dissemination vehicle for many organisations and considered important reading throughout the world. The problem, it was not getting any easier to find. Consequently, both the Commission of the European Communities and the British Library Lending Division came together to form a very important database for grey literature called SIGLE or System for Information on Grey Literature in Europe.
This bibliographic database covers nonconventional European literature in the fields of pure and applied sciences, and technology. By 1984, social sciences, economics, and the humanities were also included. SIGLE gives access to grey literature such as discussion and policy documents, research reports, theses, working and conference papers, and some important official publications, with citations in English. Grey literature is increasing in quantity because it has the advantages of flexibility and speed, and allows those who write and issue it to be concise, exact, and focused.
Problems if ID and acquisition
The core reasons for difficulties in identifying and acquiring this kind of literature are due to its "poor bibliographic information and control, non- professional layout and format, and low print runs." The implementation of bibliographic control through ISBN, ISSN, and report numbers has been somewhat helpful, but also disorganised.
Reports, making up the lion\\'s share of grey literature, do not as a rule use ISBNs, which require a depository. Instead, report numbering was initiated as a means to introduce standardisation. The problem is that these numbers were designed to include subject matter, date, form, agency, security classification, location, and additional data, and consequently, are long and confusing.
Given the nature of the literature, some categories contain security restrictions Non-availability may be due to "incomplete or incorrect identification," since accession or report numbers must be correct to attain access.
Many attempts have been made to provide sourcing for grey literature, including: the Griseli Project in France; the UK\\'s British Library Document Supply Centre; the Russian Union Catalogue of Grey Literature; and SIGLE, maintained and operated under the auspices of the European Association for Grey Literature Exploitation (EAGLE).
Other national gray literature sources
AGRINDEX database is available for life sciences and agriculture, but to date, very few grey literature documents are found in it. Energy and aerospace sciences are predominate in STAR (Scientific and Technical Reports) trough NASA. Many other countries have appointed organisations to keep track of the grey literature being produced. The Canada Institute for Scientific and Technical Information (CISTI) has a network set up to provide information to scientists and researchers, operating a document delivery service that has 3m titles in its database, and 2m technical reports on microfiche.
The United States issues a general index of government publications and technical reportsin the Monthly Catalog of US Government Publications. Other publications report the work commissioned by the United States government, but use the minimalist approach of few details, no abstracts, and no indexes. In addition, the International Federation of Library Associations (IFLA) developed UAP or the Universal Availability of Publications programme, supported by UNESCO, and offers a wide range of educational, scientific, social, economic, and technical materials to anyone anywhere.
Grey literature is sometimes available through exchange agreements with other organisations or by subscription. Annual subscriptions are expensive, but convenient if complete subject coverage is needed. Other facilities include UNESCO book coupons, monthly standing orders, and the use of a company such as Communicating Science, to find the information, or Crimdoc, which maintains a criminology library database for grey literature from the criminology field. Currently, many items can be purchased through booksellers and subscription agents as the scope of the literature is growing.
Overall, there are some important points to remember if there is to be a request for grey literature, namely: if there is a known ISBN use it. Reports are often issued what are called accession or report numbers that can be crucial for identification; and the date, author, title, and originating body will be expected.
Translations can be found in UNESCO\\'s Index Translationum, through the International Translations Centre, the British Library Document Supply Centre, the Consolidated Index of Translations in English, the Naval Ocean Systems Center, and the Canadian Index of Scientific Translations, among other sources.
Meeting papers prove to be more difficult in obtaining, but Simonton\\'s Directory might be helpful.
The Internet already creating its own equivalent of grey literature will revolutionise access to some kinds of material, but it is so easily lost in the chaos, that very few people can sift through. Solutions for its identification, acquisition, and cataloguing are far from solved, and need universal cooperation and consensus.
Augur, Charles P. 1989. Information Sources in Grey Literature. London: Bowker-Saur
Debachere, M. C. Problems in obtaining grey literature. IFL4 Journal, 21(2) 1995, p. 94-98.
Hirtle, Peter. 1991. Broadsides vs. Grey Literature.
Available: http://www-cpa.stanford.edu/byform/mailing-lists/exlibris/1991/1 I/msgOO02O.htm
(June 15, 1997).
Information World. 1996. What is grey literature?
Available: http://Info.learned.co.uk/li/newswire/I 196/wiII96.htm, (June 18, 1997).
White, Herbert. 1984. Managing the Special Library. White Plains, N. Y. Knowledge Industries Publications, Inc.