Gray literature 101  

What is gray literature?

The Twelfth International Conference on Grey Literature in Prague in 2010 arrived at the following definition:

"Grey literature stands for manifold document types produced on all levels of government, academics, business and industry in print and electronic formats that are protected by intellectual property rights, of sufficient quality to be collected and preserved by libraries and institutional repositories, but not controlled by commercial publishers; i.e. where publishing is not the primary activity of the producing body."

Traditionally, the term gray literature has included:

There are also many other forms of gray literature, including: Newsletters, technical notes, working papers, white papers, patents, and more.

GRaY or GReY?

From www.greyorgray.com: 

grAy is how it's spelled in America
grEy is how it's spelled in England

 Since there are two accepted spellings, to locate information on gray/grey literature in general, search for:

(gray OR grey) literature