What do you need to cite?

You need to cite your source when you:
  • Directly quote an author
  • ​Paraphrase another author's work.
  • Use factual information that is not common knowledge.
  • Refer to another author's opinion or theory
  • Use data, images, graphs or other content that is not your original work.
  • Use any data, information or opinions that are contentious or changeable even if they are commonly known.

What is common knowledge?

Common knowledge is basic, widely known information that doesn’t need a citation. If most people in your audience already know it—or could easily look it up in many places—it’s probably common knowledge.  

Examples of common knowledge:
  • Historical dates
    Canada became a country in 1867.
  • Famous facts
    John A. Macdonald was Canada’s first prime minister.
  • General statistics
    Canada has a population of over 30 million.
  • Widely known cultural facts
    Canada has two official languages: English and French.

​Not common knowledge (needs a citation):
  • Specific statistics
    e.g. “Only 17.9% of Canadians speak both English and French.”
  • Unique ideas or theories
    e.g. A historian’s argument about the impact of Pierre Trudeau’s policies.
  • Quotations
    e.g. “Just watch me.” – Pierre Trudeau
  • Charts, graphs, or visuals from a source
    e.g. A graph showing bilingualism rates across provinces.
  • Specialized facts
    e.g. Details about constitutional changes in 1982.
  • Controversial or debated claims
    e.g. “Trudeau’s leadership caused long-term division in Western Canada.”

💥Pro Tip: If you’re not sure whether something needs a citation, it’s safer to cite it than risk plagiarism.

A heads up for Psychology 11 students:

From this point on the information on this page is about MLA style, but in Psychology 11, we use APA style. Here's a helpful guide to get you started with APA formatting:

How to Write In-Text Citations In MLA Format:

You may find these resources will help you better understand how to write in-text citations:
All materials cited within your paper should be included in your list of Works Cited.

What to Include in In-Text Citations:

📚 For Sources with Page Numbers:
  • Include the author's last name and the page number in parentheses
  • Place the citation at the end of the sentence, before any punctuation
  • Do not include a comma between the name and number
  • Used for books, magazines, journals, PDFs, etc.

🌐 For Sources without Page Numbers:
  • Include author's last name in parentheses
  • Place the citation at the end of the sentence, before any punctuation
  • For media sources (films, podcasts, music), include a timestamp (e.g. 00:02:15–00:03:00)

How to Cite Your Sources in Different Situations:

📚 For Sources with Page Numbers: 
  • If you mention the author's named in sentence, include only the page number.
    In her popular book, Quiet, Susan Cain argues that where we fall on the introvert-extrovert spectrum will shape our lives as much as our gender or race (2).
 
  • If the author is not named in sentence, include the last name and page number.
    Winston Churchill’s grandfather also served in Parliament (Jenkins 4).
​
  • If you mention the author's name when quoting them, include page number only.
    After studying the ruins of Great Zimbabwe, Gertrude Caton-Thompson concluded that they had been built by a "native civilization [of] . . . originality and amazing industry" (17).
 
  • If you quote someone without naming them, include both their last name and the page number.
    “When paleoanthropologists refer to figurines as Venuses, [they] usually do so with air quotes" (von Petzinger 95) because Venus figurines pre-date myths about the goddess Venus by thousands of years. 
🌐 For Sources without Page Numbers: 
  • If you clearly refer to the source in a way that makes it easy to find in your Works Cited, you don't need a citation.
    Saving Private Ryan's director, Steven Spielberg, has been applauded for accurately capturing the horror and chaos of the D-Day landings in World War II.
 
  • If the author is not named in the sentence, and you paraphrase or quote them, include the last name in your citation.
    Thanks to Hollywood, many people believe that gladiatorial combat was the most popular form of entertainment in the Roman Empire, but their favourite sport was actually chariot racing (Trueman).
​
  • If you cite a time-based media source, include a time stamp for where the information came from.
    For prehistoric hunter-gatherers, the most successful hunting method was fishing, which explains why most early human settlements are found near rivers and coastal areas ("Agricultural Revolution" 00:02:20-00:02:44).​
✨ Citations for Special Cases: 
  • If the source has two authors, include both authors' last names and a page number (when needed).
    The French Revolution changed Europe forever as ideas like liberty, equality and nationalism would spread to other countries (Palmer and Colton 24).
 
  • If the source has three or more authors, include the last name of the first person on the author's list and then the abbreviation et al. (and others). You should also include a page number (when needed).
    Western civilization's moral code and work ethic are closely tied to the teachings of Christianity (Kishlansky et al. 142).
​
  • If the source doesn't have an author, include a shortened form of the title and a page number (when needed).
    Beowulf proudly declares his bravery when he says, "I have never known fear; as a youth I fought / In endless battles" (Beowulf 2511-2512).​
 
  • If the source is from a corporation or government body that doesn't credit its authors, use a shortened version of the organization's name and a page number (when needed).
    The ancient city of Petra in Jordan is described as "one of the world's richest and largest archaeological sites" (UNESCO).
 
  • If you are citing multiple works by the same author, include the author's last name, a comma, and then a shortened form of the source's title. You should also include a page number (when needed).
    Churchill's leadership was instrumental in helping the English endure the Battle of Britain (Trueman, "Churchill"), but he could not have planned a successful invasion of Europe without Eisenhower (Trueman, "D-Day").
​​
  • If you are citing multiple authors with the same last name, differentiate them with an initial. Include their full name if they have the same initials. Add a page number (when needed).
    Recent studies have shown that rising ocean temperatures will disrupt multiple ecosystems (A. Lee 142). Coral reef habitats are one of many that will be disrupted, if not destroyed, by climate change (F. Lee).
 
  • If you are citing an interview, a lecture or class notes, provide the speaker or instructor's last name only.
    During Mansa Musa's opulent pilgrimage to Mecca in 1324, many Europeans and Arabs learned about the riches of West Africa for the first time (Liew).
 
  • If you are quoting someone who was quoted in another source, use the abbreviation qtd. in (quoted in) followed by the appropriate citation for the source of the quote. 
    During the Blitz, Churchill urged Londoners to be brave, so future generations would say that "this was their finest hour" (qtd. in Miller 37).