Grey literature. This quick helpguide will explain what grey literature is and how to access it (.pdf)
« … Some information valuable for academic research and study is not published in conventional publications such as books and journals. These information sources can be challenging to locate and as such are often referred to as ‘grey literature’. The type of information covered includes translations, government information, ephemeral documents, personal communications, theses, reports and documents published by groups which are not distributed by commercial publishers.
The majority of this information is not peer-reviewed so you need to ensure you evaluate it thoroughly – advice on evaluation is available in Skills Plus. What is labelled ‘grey literature’ can vary between groups or individuals, so this guide signposts key resources rather than giving a comprehensive listing (…) »
source > northumbria.ac.uk, août 2014