Google searching can be a useful tool for finding documents that are not indexed in traditional databases, or even GoogleScholar. Leveraging some of Google's advanced searching features can help optimize a search.
Using quotation marks asks Google to locate an exact phrase
For instance: health insurance "policy brief"
This search will only retrieve results that contain the specific phrase "policy brief"
Use the site search function to ask Google to look in a specific site, or a specific kind of site.
For instance: health insurance site:.edu
This query will retrieve results only from sites that have an .edu domain.
You can also perform a site search on a specific website.
For instance: drug costs site:kff.org
This query will look for any mention of drug costs on the Kaiser Family Foundation website
File Type Search
Use the file type search function to ask Google to retrieve a specific kind of file.
For instance: "policy brief" filetype:pdf
This query will only return links to PDFs that mention "policy brief" in the document. Also consider filetype: filetype:doc for Microsoft Word Documents, filetyple:xls for Excel files (which might be useful if you're looking for raw data), or filetype:ppt if you're interested in locating PowerPoint presentation materials.
Google automatically places AND between search terms, but you can use OR to combine queries where either term would be relevant.
For instance: drug OR pharmaceutical
You can exclude terms from your search using the minus sign (-).
For instance: drug -marijuana
This query will retrieve only hits that don't contain the word marijuana.
materials not published commercially or indexed by major databases
"Fugitive," "ephemeral," "invisible" literature that may be unpublished, unevaluated, not peer-reviewed
"Information produced on all levels of government, academics, business and industry in electronic and print formats not controlled by commercial publishing i.e. where publishing is not the primary activity of the producing body." (Luxembourg, 1997 - Expanded in New York, 2004, http://www.greynet.org/)
Grey Literature may exist in any number of formats:
conference abstracts and proceedings
informal communication (that may include interviews, blog postings, podcasts, personal communication such as email)
A clinical trial registry recognized by the WHO and ICMJE that accepts planned, ongoing or completed studies of any design. Originally, ISRCTN stood for 'International Standard Randomised Controlled Trial Number'; however, the scope of the registry has now widened beyond randomised controlled trials to include any study designed to assess the efficacy of health interventions in a human population. This includes both observational and interventional trials.
The Agency for Healthcare Research and Quality (AHRQ)'s publications offer practical information to help a variety of health care organizations, providers, and others make care safer in all health care settings.
Formerly the Virginia Henderson Global Nursing e-Repository, the Sigma Repository is dedicated to sharing works created by nurses around the world. It is an open digital academic and clinical focused service that freely collects, preserves, and disseminates full-text nursing research, educational, and evidence-based practice materials in a variety of formats and item types.
OpenDOAR is the quality-assured, global Directory of Open Access Repositories. You can search and browse through thousands of registered repositories based on a range of features, such as location, software or type of material held.
F1000Research is an open research publishing platform, offering rapid publication of articles and other research outputs across physical and life sciences, engineering, medicine, social sciences and humanities.
PAIS International contains journal articles, books, government documents, statistical directories, grey literature, research reports, conference reports, publications of international agencies for public affairs, public and social policies, and international relations.
The Health and Medicine Division (HMD) of the National Academies (formerly Institute of Medicine, IOM) publish reports that provide objective and straightforward advice to decision makers and the public.
Think Tank Search searches the websites of institutions that generate public policy research, analysis, and activity. These sites are affiliated with universities, governments, advocacy groups, foundations, and non-governmental organizations.
Preprints for the psychological sciences including clinical psychology, neuroscience, and other subject areas. Created by the Society for the Improvement of Psychological Science and the Center for Open Science.
Web of Science: All Databases (formerly Web of Science Plus; Web of Knowledge) allows you to cross-search databases in a variety of subjects, including: Web of Science Core Collection, Biological Abstracts, BIOSIS Previews, Food Science and Technology Abstracts, Medline, and Journal Citation Reports.