Recently, I received an Email from Anthony Haynes from Frontinus Ltd., http://frontinus.org.uk, in England. He helps, especially engineers, to write successful academic articles and books.[1] In his latest research paper,[2] he deals with the importance of grey literature.

Grey literature is a form of knowledge that serves beyond peer-reviewed journals, especially for the exchange of ideas by practitioners. Academics also use it as a medium for exploring and discussing ideas in the preliminary stages of a scientific publication.