Search databases to find articles available through CSU Libraries to find journal articles and other types of articles (newspaper, magazine, conference papers, etc.) related to your topic.

Each database contains a information from different subject areas and time periods. Read the description of each database underneath the title and ask a librarian if you have any questions about which database to search.

Search Terms & Connectors (AND, OR, NOT)

Keyword Connectors: AND, OR, NOT

Use AND, OR, and NOT to connect keywords and target your results. 

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Searching Tips

Search with a purpose

Knowing the ultimate purpose that your search results need to serve will help select resources to search, formulate search strategy, and, ultimately, assess results.

Keeping the purpose for your search in mind helps you prioritize which results you should review in-depth versus which ones you can skim for information or mine for references.

Possibilities may include

  • I need to find information about a topic for an assignment
  • I need to find information that answers a clinical question
  • I need to find articles that are similar to an article that I find useful

Identify search terms

Now it is time to look at search terms - the words that you will actually type into the database to return the best results.

Helpful questions to ask when identifying search terms

  • What would the ideal title or abstract look like for my information need? What terms might be included?
  • Are there common or slang terms for any of my terms?
  • Are there acronyms for any of my terms? 
  • Are there any other synonyms for any of my terms?
  • Are there terms that are similar to any of my terms that I need to exclude from my search?
  • Are there alternate spellings for any of my terms?
  • Common spelling differences may include
    • Anesthesia, anaesthesia
    • Orthopedics, orthopaedics,
    • Hematology, haematology
    • Color, colour

Identify appropriate resources to search

Each database contains information from different subject areas. Even though there may be overlap between databases, each is unique in its content and interface. Below are several "best bets" for biomedical sciences with their strengths and a few points of awareness. 

Contact the librarian if you have questions about which resources or how many resources are appropriate for your research.



  • Comprehensive coverage of nursing and allied health literature
  • May return items not retrieved with PubMed/MEDLINE

Points of Awareness

  • Requires a formulated search strategy (is not as easy to search as PubMed/MEDLINE) using a combination of keywords (either searching the full text or limiting to title and/or abstract) and subject headings (found in the thesaurus)



  • Easy search functionality with automatic mapping of search terms to medical subject headings (MeSH)
  • Filters and subject headings can be used to easily identify study types (systematic reviews, RCTs, clinical trials, etc.)
  • Clinical queries option to target search results for disease diagnosis, etiology, prognosis, therapy, and clinical prediction guidelines

Web of Science

Includes option to search BIOSIS Citation Index


  • Search citations from thousands of scientific and interdisciplinary journals
  • Easily pull citations entire reference lists for articles you find useful
  • Find articles that cite articles you find useful 
  • Find journals, authors, and organizations that publish on a topic 

Points of Awareness

  • Does not have controlled vocabulary (subject headings). For searches that result in a large number of results, try limiting a key term to just searching the Title. 


In this section

Search operators, including Boolean operators, wildcards, truncation, and proximity operators, all help target and refine your search.

The basics of search construction are Boolean operators (AND, OR, NOT). Using Boolean operators in between search terms tells the database what to search for, what to exclude, and in which order to perform these operations.

To force the database to read your search query that way you need it to, use parentheses to dictate which operators are read in which order by making the database read the terms inside the parentheses before the terms outside the parentheses.

Remember to look for the FindIt Button to access articles button when searching the library website, databases, or Google Scholar to help you get to the full-text of articles. 

Search Operators

Operator Action Uses


retrieves only results that contain all terms Narrows the search


retrieves results containing one or all terms Expands the search


excludes results containing the term associated with NOT Narrows the search

Truncation (*)

Searches for all terms that start with the root (the part of the word before the *) Expands the search

Wildcard  (?) (#)

Searches for spelling variations within a word. 

  • # (EBSCO)
  • * or ? (Web of Science)
Expands the search

Proximity (N) (NEAR)

Searches for terms within a certain number of words of another term. The number (represented by # below) is determined by the user and entered as a numeral (N3, for example).

  • N# (EBSCO)
  • NEAR# (Web of Science)
Narrows the search

Phrase searching ("")

Putting quotations around a phrase ("kidney disease," for example) will search for that phrase as it appears within the quotation marks. Narrows the search

Examples of Boolean searches

lions AND tigers Results will only include records that contain both search terms (lions and tigers)
lions OR tigers Results will include records about lions and tigers, about lions, and about tigers
lions NOT tigers Results will include records about lions and will exclude articles about tigers
(lions AND (tigers OR bears)) NOT zebras

Results will include records about

  • lions and tigers, but not zebras
  • lions and bears, but not zebras
  • lions and tigers and bears, but not zebras 
((lizards OR snakes) AND (diet OR prey)) NOT (salamanders OR eels)

Results will include records about

  • lizards and diet
  • lizards and prey
  • snakes and diet
  • snakes and prey
  • lizards and snakes and diet
  • lizard and snakes and prey
  • snakes and diet and prey
  • lizards and diet and prey

and will exclude any records about salamanders and/or eels

(((cat* OR feline*) NOT (lion* OR tiger*)) AND ("kidney disease" OR "renal disease" OR CKD OR "renal failure")) AND hyperthyroidism

Results will include records about

  • cats and kidney disease/renal disease/CKD/renal failure and hyperthyroidism
  • felines and kidney disease/renal disease/CKD/renal failure and hyperthyroidism

and will exclude any records about tigers and/or lions

cattle N3 beef Results will include records with the word "cattle" within three (3) words of "beef"

Combining Searches Using Search History

Most databases offer a Search History function that allows you to combine previous searches and review results. This is a great option for systematic or iterative searching, or if you like to search with smaller search strings instead of lengthy ones. 

Combining searches lets you view what types of results you get for each piece of a search before combining it to view the results. 

For one of the examples above, it might look like this:

S1 (Search 1)     (((cat* OR feline*) NOT (lion* OR tiger*))

S2 (Search 2)     ("kidney disease" OR "renal disease" OR CKD OR "renal failure"))

S3 (Search 3)     hyperthyroidism

S4 (Search 4)     S1 AND S2

S5 (Search 5)     S1 AND S3

S6 (Search 6)     S1 AND S2 AND S3

Subject Headings (controlled vocabulary)

Databases like PubMed/MEDLINE and CAB Abstracts use forms of controlled vocabulary to classify records for items (articles, book chapters, etc.) in their indexes. These are not free-text search terms, they are assigned to each item to reflect the item's topic. Subject headings are a way to retrieve items on a topic, even if different terms are used to describe the topic in the actual item. 

PubMed/MEDLINE uses search headings called Medical Subject Headings (MeSH) and automatically maps natural language search entries to MeSH. There is a MeSH browser where you can search for MeSH term, see in which year it was introduced (only articles indexed after that time will have the term), and add them to a search. 

Other databases, such as CAB Abstracts, have a Thesaurus in the top left corner of the page where you can search for and browse search terms and add them to a search. 

Subject headings can be used in conjunction with keywords to help focus a search, but keep in mind that several subject headings may relate to your search.

Types of Review Articles

Systematic reviews and meta-analyses carry the most weight in evidence-based clinical practice. Although they do not rank in the evidence hierarchy for evidence-based practice, scoping reviews and narrative reviews can provide useful summaries and information that can give background about a topic or point to useful research studies. All types of review articles can be useful for researchers, as the references provided (the literature that the literature reviewer reviewed) may be relevant to the researcher's question or interest. 

References: Foster M, Jewell S. (2017). Assembling the pieces of a systematic review: a guide for librarians. Lanham, MD: Rowman & Littlefield Publishers. ISBN 9781442277014

Types of Research Studies

Is a journal peer-reviewed?

Some databases have filters to select only material from peer-reviewed journals. To see if a journal is peer-reviewed (scholarly, refereed), look up the journal title in Ulrich's and look for the referee jersey icon (see below). This means that the journal is refereed (peer-reviewed).




Research study methodologies

Questions to ask when assessing research methodology:

  • Is the research question and hypothesis clearly defined?
  • Are the methods and measurements detailed enough so that the study is reproducible?
  • Were the comparison groups truly comparable?
  • Were patients in each group randomized?
  • Was the study blinded or double-blinded? 
  • What was the dropout rate and was the dropout rate explained?
  • Was the timeline long enough to allow for all possible or relevant outcomes?
  • Were the comparison groups treated equally? 
  • Did the authors disclose funding sources?

There are various acronyms, organizations, and guidelines that are widely used to assess research study methodologies and quality. The EQUATOR Network provides detailed information and links for each study type. Below is an abbreviated list.

Study Type Reporting and Methodologies Guidelines
Randomized controlled trials (RCTs) CONSORT

Systematic reviews



Cochrane Collaboration

Joanna Briggs Institute

Clinical Trials CONSORT
Observational studies STROBE
Case reports CARE
Animal pre-clinical studies ARRIVE
Study protocols SPIRIT


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