Google fundamentally changed the accessibility of grey literature. Prior to Google, grey literature was characterized by a lack of persistence. Items were frequently lost to history due to limited distribution and the regional nature of the holdings.

Google made it possible to discover items, regardless of physical location. Therefore, it reduced the difficulty of discovery. Additionally, professional organizations created discovery tools that can assist with discovery as well.

Accessibility remains a problem. As noted above, many libraries do not catalog grey literature and have not digitized the items.  Accessing the items frequently requires that you know where it is held and make a direct request to access the item, either by traveling to it or by inter-library loaning the item.

Search Strategy

When developing your search strategy for finding a known grey literature item,

• start with the institutional author/publisher information
• if it exists, determine any identification number.
  • Some will have numbers that are assigned by the institutional publisher.
  • Others will have ISSNs or ISBNs, depending upon how the item is cataloged.
• Identify likely repositories for the information based upon the author and the type of grey literature that it is. These could be commercial databases but could also be governmental or non-governmental repositories.
• Use Google to develop a search string that highlights author, publisher, identifier and type of grey literature.
• Develop a search strategy for the individual repository or index that you are searching from.

When searching for an unknown item,

• Pick a likely repository or search engine based on your knowledge of the contents held there. Use a pre-programmed ("pre-canned") search such as those listed below if you don't know where to start.
• Use full text searching strategies such as quotes and proximity searching/NEAR to indicate the content that you are interested in.
• If you have a desired institutional publisher, create a string surrounded by quotes to further limit the results
• If you have a desired date range, specify it using appropriate syntax.

Google Scholar is preferable to the general Google search when searching for grey literature.   The following can be helpful in developing a Google search strategy for grey literature:

• site: Limit to website of the institutional author/publisher information or a known repository
• " Word or Phrase ": search for a character string corresponding to the identifier, the individual title of the volume, or the serial title for the volume
• allintitle: "Word or Phrase": search for a character string corresponding to the individual title of the volume
• author: "Word or Phrase" search for variations of an individual author name
• yyyy .. yyyy: search for a date range for the item you are looking for by placing two periods between the desired year range
• In advanced search (left side bar), you can also search by publication field, which allows you to search for the institutional author.

Example Known Item Search in Google Scholar:

Coburn AS and Others. 2010.  Natural Resource Technical Report. NPS/NRPC/GRD/NRTR—2010/373. Natural Resource Program Center. Fort Collins, Colorado

I have this incomplete citation. To search for this item, I will start by

• identifying the institutional publisher, the National Park Service, so I will limit my search to nps.gov.
• I don't have a title, so I move to the identifier, which is 2010/373

Search strategy:

site:nps.gov AND "2010/373"

Example General Grey Literature Search in Google Scholar:

If I have a prompt to find grey literature about the Golden Gate bridge in the years of its planning and construction, I will need to identify:

• The topic: Golden Gate bridge
• A likely institutional publisher: In this case, a government agency seems like a likely place to start
• Date search: the date range of the items I am looking for

Search strategy: site: .gov AND "golden gate" AND 1900..1937