In general, books and journal articles will be the main sources of information for your academic work. However, a number of other reliable sources of information are available. You can search for all of these in Library Search. These include:
Conference Papers - academic papers presented at conferences
Working Papers - pre-publication academic research papers
Theses and Dissertations
Official Publications - publications by national governments and IGOs
Core is the world’s largest collection of open access full text research papers - aggregating and enriching open access research papers from around the world. CORE will supply data for the UK REF 2021 Open Access Policy Audit to Research England.
System for information on Grey Literature in Europe. Open Grey is a multidisciplinary European database, covering science, technology, biomedical science, economics, social science and humanities. The records are in English. They include bibliographical data, the SIGLE classification codes with their wording, and possibly an English abstract (starting in 1997).
OpenGrey is operated by INIST-CNRS. OpenGrey combines the resources of major European information and document supply centres (including the British Library) who joined in an association known as EAGLE : European Association for Grey Literature Exploitation. Each centre was responsible for collecting grey literature produced in its own country. It also helps you to obtain a copy of the paper document, if no other information is available in the reference.