Systematic Reviews: Grey Literature

Grey literature is a term to describe information which is produced outside of traditional publishing and is often not indexed on databases. These publications can help compliment your research by providing a rigorous and complete overview of research on a particular area.  Grey literature can be a great source of statistics and data and can take many different formats. Below is a list of some of these formats:

• Blogs                                                 
• Conference papers/proceedings
• Datasets
• Discussion lists
• Dissertations and theses
• Government reports
• Newsletters
• Pamphlets
• Preprints
• Policies and guidelines
• White papers
• Working papers 

Introduction to Grey Literature:

• ▶️ Grey Literature Tutorial - Western University              
• ▶️ Gray Literature: an introduction - UNC Libraries
• ▶️ Grey Literature - Welsh Medical Library

Searching for Grey Literature:

• ▶️ Finding Grey Literature - FlindersInfo Tech     
• ▶️ How to source grey literature - Murdoch University Library                 
• ▶️ Grey Literature: what it is and how to find it - The Levy Library

Searching TRIP Database:

• ▶️ Search module intermediate video 3 searching the TRIP database - McGill Library
• ▶️ Searching the TRIP database - OUTulsaLibrary

File type searching

Google can search for documents that are available online based on their file format. This could be a more effective way to find grey literature than simply Googling because documents such as policy guidelines are more likely to be published in PDF format. To do this, type filetype: followed by the file format with no spaces. For example:

• filetype:pdf will search for PDF documents
• filetype:ppt will search for PowerPoint presentations
• filetype:doc will search for Word documents
• filetype:xls will search for Excel spreadsheets

Example:

filetype:pdf anaesthesia guidelines

Note that newer documents created in Microsoft Office often have an 'x' on the end (e.g. docx instead of doc). You will need to search for these separately.

Domain searching

You can ask Google to search individual websites or groups of websites sharing a domain. To do this, type site: followed by the web address or domain without any spaces. For example:

• site:nhs.uk would search NHS websites.
• site:gov.uk would search UK government websites
• site:ac.uk would search UK university websites

Example:

site:nhs.uk anaesthetic guidelines

You can combine this with file type searching and domain searching. For example, search site:gov.uk filetype:pdf to find UK government reports.