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BY 245/555: Biological Data Interpretation and Analysis: Cite Sources

APA Style Manual

APA Style is a citation style used in scientific disciplines developed by the American Psychological Association.

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Credit Sources

Plagiarism is the act of presenting the words, ideas, results, or images of another as your own.  To avoid plagiarism, credit sources by adding in-text citations with matching references formatted in APA Style.  For more information, consult the avoiding plagiarism guide.

Paraphrase  

  • restate the idea from another work in your own words

The occurrence of cholera is rare in the United States and the few cases per year is usually due to contaminated food or international travel (Centers for Disease Control and Prevention, 2018).

Centers for Disease Control and Prevention. (2018, May 11). Cholera: Sources of infection and risk factors. https://www.cdc.gov/cholera/infection-sources.html

Quotation

  • reproduce the words verbatim from another work
  • enclose in double quotation marks and include page or paragraph number

According to the Centers for Disease Control and Prevention (2018), "if left untreated, 25-50% of severe cholera cases can be fatal" (para. 1).

Centers for Disease Control and Prevention. (2018, May 11). Cholera: Sources of infection and risk factors. https://www.cdc.gov/cholera/infection-sources.html

For more information, consult the paraphrasing and quotation guidelines.

In-Text Citations

In-text citations appear within the body of the paper and briefly identify the cited works by author name and publication year.  For more information, consult the in-text citation guidelines.

There are two formats for in-text citations:

Parenthetical Citation

  • author name and publication year appear in parentheses separated by a comma
  • usually appear at end of the sentence (can also appear within the sentence)

Human infection with Vibrio cholera, a gram-negative motile rod causing cholera, begins with ingestion of contaminated food or water containing the bacterium (Halpern & Izhaki, 2017).

Vibrio cholera may have a mutualistic relationship with fish since they “provide food and shelter for this bacterium while the bacterium may assist the fish to digest its food” (Halpern & Izhaki, 2017, p. 5).

Narrative Citation

  • author name is incorporated into the text as part of the sentence and the publication year follows in parentheses
  • usually appear at beginning of the sentence (can also appear within or at end of the sentence)

According to Halpern and Izhaki (2017), human infection with Vibrio cholera, a gram-negative motile rod causing cholera, begins with ingestion of contaminated food or water containing the bacterium.

Halpern and Izhaki (2017) state that Vibrio cholera may have a mutualistic relationship with fish since they “provide food and shelter for this bacterium while the bacterium may assist the fish to digest its food” (p. 5).

For more information, consult the parenthetical versus narrative in-text citation guidelines.

The formatting of in-text citations varies depending on the number of authors.

Author type Parenthetical citation Narrative citation
One author (Derby, 2020) Derby (2020)
Two authors (Aggio & Kamio, 2020) Aggio and Kamio (2020)
Three or more authors (Johnson et al., 2020) Johnson et al. (2020)
Group author (Harvard University, 2020) Harvard University (2020)

Group author with abbreviation

     First citation

     Subsequent citations

 

(World Health Organization [WHO], 2020)

(WHO, 2020)

 

World Health Organization (WHO, 2020)

WHO (2020)

For more information, consult the author-date citation system guidelines.

References

References appear in an alphabetical list at the end of the paper and provide the information necessary for the reader to identify and retrieve each work cited in the text.  For more information, consult the references guidelines.

There are four elements in references:

  • Author – Who is responsible for the work?
  • Date – When was the work published?
  • Title – What is the work called?
  • Source – Where can the work be retrieved?

For more information, consult the elements of reference list entries guidelines.

One Author

  • list the author by last name followed by a comma then the initial(s)

Derby, C. D.


Two Authors

  • list both authors in the order given on the source, use a comma to separate the authors, and include an ampersand between the authors

Aggio, J. F., & Kamio, M.


Three to Twenty Authors

  • list all authors in the order given on the source, use a comma to separate the authors, and include an ampersand before the last author

Jonhson, P. M., Nusnbaum, M., & Sheybani, A.


More Than Twenty Authors

  • list the first 19 authors and include three ellipsis points (for omitted names) before the last author (should be no more than 20 names)

Nusnbaum, M., Aggio, J. F., Derby, C. D., Kicklighter, C. E., Shabani, S., Johnson, P. M., Carefoot, T. H., Pennings, S. C., Danko, J. P., Kamio, M., Nguyen, L., Grimes, T. V., Hutchins, M. H., van Dam, R., Schmidt, M., Paul, V. J., Sheybani, A., Caprio, J., Yaldiz, S., . . . Steinberg, P. D.


Group Author

  • list the full name of the group author

Centers for Disease Control and Prevention.


Name Variants

  • use the examples below for author name variants

           Holland, N. T. J.
           Smith Thomas, P.

 Stuart-Fox, D.
Yang, Z.-X.		             Cooper, W. E., Jr.
            Moore, R. M., III.		 de Mesa, A.
Van Camp, L. B.

Consult the resources below for more information about reference entries.

Book Template

Author, A. A. (Year of publication). Title of book: Subtitle of book (edition). Publisher. https://doi.org/xx.xxx/yyyy

McCarthy, M. (2019). Superbugs: The race to stop an epidemic. Avery.

Amabile-Cuevas, C. (2016). Antibiotics and antibiotic resistance in the environment (2nd ed.). CRC Press. https://doi.org/10.1201/b19549


Chapter in Edited Book Template

Author, A. A. (Year of publication). Title of chapter. In E. E. Editor (Ed.), Title of book: Subtitle of book (edition, pp. pages). Publisher. https://doi.org/xx.xxx/yyyy

Marrollo, R. (2016). Microbiology of Bacillus cereus. In V. Savini (Ed.), Diverse faces of Bacillus cereus (pp. 1-13). Academic Press. https://doi.org/10.1016/C2013-0-19333-6

Prince, C. W. (2010). General stress response in Bacillus subtilis and related gram‐positive bacteria. In G. Storz & R. Hengge (Eds.), Bacterial stress responses (2nd ed., pp. 251-289). ASM Press. https://doi.org/10.1128/9781555816841

Journal Article Template

Author, A. A. (Year of publication). Title of article. Title of Journal, volume number(issue number), pages. https://doi.org/xx.xxx/yyyy

Friedman, N. D., Temkin, E., & Carmeli, Y. (2016). Negative impact of antibiotic resistance. Clinical Microbiology and Infection, 22(5), 416-422. https://doi.org/10.1016/j.cmi.2015.12.002

Richardson, L. A. (2017). Understanding and overcoming antibiotic resistance. PLoS Biology, 15(8), Article e2003775. https://doi.org/10.1371/journal.pbio.2003775


Online Magazine Template

Author, A. A. (Date of publication). Title of article. Title of Magazine. URL

Kimmer, K. (2019, May 23). How bacteria become drug-resistant while exposed to antibiotics. The Scientist. https://www.the-scientist.com/news-opinion/how-bacteria-become-drug-resistant-while-exposed-to-antibiotics-65929

National Institutes of Health. (2018, January 25). End of antibiotics? NIH MedlinePlus Magazine. https://magazine.medlineplus.gov/article/the-end-of-antibiotics

Web Page Template

Author, A. A. (Date of publication). Title of page. Site Name. URL

World Health Organization. (2020, July 31). Antimicrobial resistance. https://www.who.int/news-room/fact-sheets/detail/antimicrobial-resistance

Harris, R. (2019, November 13). How best to use the few new drugs to treat antibiotic-resistant germs? NPR. https://www.npr.org/sections/health-shots/2019/11/13/778261164/with-few-new-drugs-to-treat-antibiotic-resistance-how-best-to-deploy-them


Blog Post Template

Author, A. A. (Date of publication). Title of post. Blog Name. URL

Delvin, M. (2020, August 26). Antimicrobial resistance: The next pandemic? Microbe Post. https://microbiologysociety.org/blog/antimicrobial-resistance-the-next-pandemic.html

Farrell, S. (2016, July 22). Trouble with antibiotics. Harvard Health Blog. https://www.health.harvard.edu/blog/the-trouble-with-antibiotics-201607209986

Reference list contains all of the works cited in the text.

Order the entries in the reference list as follows:

  • arrange entries alphabetically by author (or title if no author) with nothing before something
  • arrange entries with same author(s) by year of publication with earliest first
  • arrange entries with same author(s) in the same year alphabetically by title and add suffix to year

Applegate, J. T.
Applegate, J. T., & Swanson, E. K.
Chapple, D. G. (2018).
Chapple, D. G. (2020a). Distribution of
Chapple, D. G. (2020b). Effects of
Thorton, R. W.


Format the reference list as follows:

  • start the reference list on a new page at the end of the paper
  • label as References (centered in bold) at the top of the page
  • double space reference list and apply hanging indent


For more information, consult the creating a reference list guide.

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