Grey literature (or gray literature) is materials and research produced by organizations outside of the traditional commercial or academic publishing and distribution channels. Common grey literature publication types include reports (annual, research, technical, project, etc.), working papers, government documents, white papers and evaluations. Organizations that produce grey literature include government departments and agencies, civil society or non-governmental organizations, academic centres and departments, and private companies and consultants. Grey literature may be difficult to discover, access, and evaluate, but this can be addressed through the formulation of sound search strategies. Grey literature may be made available to the public, or distributed privately within organizations or groups, and may lack a systematic means of distribution and collection. The standard of quality, review and production of grey literature can vary considerably. Definitions While a hazy definition of "grey literature" had existed previously, the term is generally understood to have been coined by the researcher Charles P. Auger, who wrote Use of Reports Literature in 1975. The literature he referred to consisted of intelligence reports and notes on atomic research produced in vast quantities by the Allied Forces during World War II. In a conference held by the British Lending Library Division in 1978, Auger used the term "grey literature" to describe the concept for the first time. His concepts focused upon a "vast body of documents" with "continuing increasing quantity" that were characterized by the "difficulty it presents to the librarian". Auger described the documentation as having great ambiguity between temporary character and durability, and by a growing impact on scientific research. While acknowledging the challenges of reports literature, he recognized that it held a number of advantages "over other means of dissemination, including greater speed, greater flexibility and the opportunity to go into considerable detail if necessary". Auger considered reports a "half-published" communication medium with a "complex interrelationship [to] scientific journals". In 1989 Auger published the second edition of The Documentation of the European Communities: A Guide, which contained the first usage of the term "grey literature" in a published work. The "Luxembourg definition", discussed and approved at the Third International Conference on Grey Literature in 1997, defined grey literature as "that which is produced on all levels of government, academics, business and industry in print and electronic formats, but which is not controlled by commercial publishers". In 2004, at the Sixth Conference in New York City, a postscript was added to