The term grey literature "is usually understood to mean literature that is not formally published in sources such as books or journal articles" (Lefebvre, Manheimer, & Glanville, 2008, p. 106).
Grey literature may include multiple types of document produced on all levels of government and by academics, businesses and organisations in electronic and print formats where publishing is not the primary activity of the producing body. (Greynet, 2015.)
There may also be grey literature that is specifically relevant to your discipline. Practice Guidelines are highly relevant to nursing and health professions, working papers are used in the social sciences (particularly economics) and patents are important to engineering.
A systematic review conducted in 2008 by members of the Cochrane methodologies team found that often the results from grey literature significantly affect the outcome of a review, as they often report more negative or inconclusive data than published journal articles (Hopewell et al., 2008). As such, it is important to treat grey literature as another potential source of studies for inclusion while noting that it is usually not subject to peer review and must be evaluated accordingly.
1. Alberani, V., De Castro Pietrangeli, P. & Mazza, A.M. (1990). The use of grey literature in health sciences: A preliminary survey. Bulletin of the Medical Library Association, 78 (4) : 358-363. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC225438/
2. GreyNet International (2015). Retrieved from http://www.greynet.org
3. Lefebvre C, Manheimer E, Glanville J. (2008). Searching for studies. In: J.P.T. Higgins & S. Green (Eds.), Cochrane handbook for systematic reviews of interventions. Chichester: Wiley-Blackwell.
4. Hopewell S, McDonald S, Clarke M, & Egger M. (2007). Grey literature in meta-analyses of randomized trials of health care interventions. The Cochrane Library. doi: 10.1002/14651858.MR000010.pub3
University repositories can be used to locate theses, research papers and data if they have been made available. You can find information about locating theses and dissertations in the Murdoch Library Theses Guide.
The Murdoch Research Repository is an open access digital collection of research created by Murdoch University staff and students.
OpenDOAR is an authoritative directory of academic open access repositories.
Australian Government Information
Government Departments (State and Commonwealth) can be found with Google. Some useful sites are listed below:
In addition to the sources listed above, internet searching can locate other useful sources:
You should evaluate grey literature as you would all information to be included in your research.
The AACODS checklist created by Flinders University is designed to enable evaluation and critical appraisal of grey literature using these criteria.