Grey Literature

All you need to know to incorporate grey literature in to your work.

Use Specific Commands to Focus Your Internet Searches

Google is a great resource for grey literature when used thoughtfully with operators.

How it Works: Popular Google Operators

Command Example What Happens?
"" "best practice" tracheostomy 

Phrase searching. Searches for words in the order entered.

+ wheelchair +skills Includes specific word(s) in results.
- "primary health care" -"primary care" Excludes specific word(s) in results.
wheelchair * test

Fills in missing word(s).

wheelchair skills test
wheelchair skills program test
wheelchair aptitude test

... cataract surgery $400...$1000

Searches specific number range (years, prices, weights, etc.).

Locates items about cataract surgery prices between $400 and $1000.

allintext:  allintext:guideline tracheostomy

Locates multiple words in body of search results.

intext:  intext:social determinants of health  Locates single word or phrase in body of search results.
allintitle:  allintitle:guideline tracheostomy

Locates words in the title of search results.

intitle: intitle:social determinants of health

Locates single word or phrase in title of search results.

define: define:craniotomy 

Locates a definition for a word or phrase.

filetype: dementia guidelines filetype:pdf

Searches by file types such as pdf, doc, ppt, etc.

site: vaccination


Searches by domain extension (.gov, .ca, .org, etc.), or within a specific website.
AROUND Plavix AROUND 3 aspirin Retrieves results that use the second word aspirin within so many words of the first word (in this example, results that use aspirin within three or fewer words of Plavix).

Tips for Using Operators Effectively:


  • Do not add a space between the command and what you are searching for
    • For example, filetype:pdf NOT filetype: pdf
  • When using the wildcard command, DO add a space before and after *
    • For example, wheelchair * test NOT wheelchair*test

Choice of Operator

  • Do not use a phrase search with the allintext: operator; use intext:
  • Do not use a phrase search with the allintitle: operator; use intitle:
  • allintext: will generally return more results then allintitle:. intext: will return more results than intitle:

File Types

  • View a full list of filetypes returned in a Google search here. Use filetype: with any of the listed extensions (pdf, ppt, doc, etc.)

Combining Operators