Grey literature refers to both published and unpublished research material that is not available commercially. Some examples of grey literature are conference papers, theses, clinical trails, newsletters, pamphlets, reports, fact sheets, government documents, surveys, and so on.
Find Grey Literature
Open Grey : open access to 700.000 bibliographical references of grey literature (paper) produced in Europe
To keep track of your search Citation management software collects citations from various sources, organizes them and complies them into a bibliography or list of works cited. The software helps create citations in many referencing styles like APA. The library supports 2 citation management software Mendeley, and Zotero
Reasons to choose
Mendeley: is a free, cloud-based, citation and PDF manager as well as an academic social network. If your research is primarily contained in PDF files, Mendeley has an integrated PDF viewer and can create citation records just from importing a PDF file
Zotero: is free software that allows you to collect, manage and cite your references. If your research content is diverse it is the easiest method to gather citation records for both PDF & non-PDF content