Earth and Environmental Sciences

What do we mean by grey literature?

Grey literature is usually defined as: "That which is produced on all levels of government, academics, business and industry in print and electronic formats, but which is not controlled by commercial publishers."*


Given that it is not controlled by commercial publishers, grey literature can be difficult to find.  Depending on your research project and topic, locating pertinent grey literature will be an essential part of the research process.   Additionally, grey literature does not always involve a peer-review process.  This means that if you choose to include these sources you must also evaluate them.

Examples of grey literature include:

  • Reports from governments
  • Reports from agencies and NGOs
  • Theses and dissertations
  • Pre-print articles (not published in a journal)
  • And much more!

*GL'99 Conference Program. Fourth International Conference on Grey Literature: New Frontiers in Grey Literature.GreyNet, Grey Literature Network Service. Washington D.C. USA, 4-5 October 1999.

Finding Grey Literature

The search strategy is key!

As with any research project, you need to start with a defined research question.  Once you have your research question you can then create a sound search strategy.  Searching for grey literature is complex and the number of results one retrieves can be overwhelming if you have not set strict parameters from the get-go.

For a brief overview on how to create a search strategy, consult the Searching Effectively and Efficiently tab on the Technical Report Writing research guide.

Identify the type of information you need

Before you blindly start searching for grey literature, determine what type of information is needed in order to complete your research project.  This will then allow you to identify which databases and search tools you need to use to complete your search. 

  • Do you require annual reports, government reports, etc.? 
  • Is the information you are seeking cutting edge? 
    • If so, where can you locate new research before it's disseminated via traditional publishing means (posters, conference proceedings, etc.)?

Document every step of your search

As with any research you conduct, documenting your process is essential. You should note the keywords that were used and the databases that were searched.  Also to facilitate citing your documents later on, keep detailed information regarding where and when the information was located.  Don't merely bookmark the website or document since these can change.  This is especially true of online reports.

You may need to repeat part of your search at a later day, and having clear notes will allow you to do so quickly and easily.  Without any documentation you won't be able to repeat your searches.

Know where to look!

Remember, there is no grey literature database.  In order to locate grey literature, you will need to use a number of research databases, search tools, and even Google.

Below you will find information to retrieve specific types of grey literature.  This is not an exhaustive list, and when in doubt contact your liaison librarian for more help.

Federal Science Library

Pre-print and Post-print articles

Pre-prints are articles that are going through the process of publication, before peer-review.

Post-prints are articles that have been peer-reviewed, but have not been formatted by publishers.

These publications can be found via various channels, whether it be on Google Scholar, institutional repositories such as uoResearch, and subject repositories.  Authors will self-archive their pre and post prints in these archives.  In some disciplines, such as mathematics, these repositories are widely used.

Some subject repositories include:

  • arXiv
    • Covered areas include physics, mathematics, computer science, nonlinear sciences, quantitative biology and statistics
  • PeerJ
  • OpenDOAR
    • Directory of open access repositories.  Useful to locate subject repositories in your discipline.

Theses and Dissertations

Theses may be available in online format within a database or institutional repository or the print format may be listed in a university library catalogue. Below, is a list of different databases that index theses and dissertations.

If the full-text thesis or dissertation is not available in the Library's collection, request an interlibrary loan.

Conference Proceedings

Locating the full-text of conference proceedings can be difficult since they are not always available online, and some are distributed in print format or even on a CD-ROM. Or they may only be available to conference participants. Below, is a list of different databases that index conference proceedings.

Locating conference proceedings in Omni

uOttawa Libraries have some conference proceedings in our collection. These volumes can be located in Omni:

  • If you know the specific volume, you can search by title, association, or series;
  • If you would like to see what the library has on a particular topic, you can search by keywords. Then, on the results page, use the search filters on the left to limit your results by resource type to "conference proceedings"

What if the conference proceeding is not available in print or electronic format?

Submit a request for an interlibrary loan. You can request an individual article or the entire volume (if available). 

Evaluating Grey Literature

All sources of information should be viewed through a critical lens.  With grey literature, there are a few additional things to look for when evaluating your sources:

  • Consider the tone of the document.
  • If statistics are included, are they cited?
  • Is there a bibliography at the end of the report?
  • Finally, is the document well written?

If you are uncertain about one of your sources, contact a librarian.