[APA Style](https://apastyle.apa.org/) is a style guide for uniform and consistent written communication first published in *Psychological Bulletin*. The APA style can be used to cite sources in a consistent format. When citing data for a report or other document, always use a single style guide (if a source recommends a citation, you may need to reformat it--make sure all provided information is included). A complete APA reference includes the ***Who***, ***When***, ***What***, ***Publisher***, and ***DOI or URL***. The [Common Reference Examples Guide](https://apastyle.apa.org/instructional-aids/reference-examples.pdf) contains many examples for a variety of source types. ## Citing Data Sets Data sets are cited in APA format in the following format. > Author or Group. (Year Published). *Title in italics* (Additional Identifiers; Version; etc.). [Data set (and codebook)]. Publisher. Link. Parenthetical (in-text) citations include the author and year published as `(Author, Year Published)`. See [the APA style reference](https://apastyle.apa.org/style-grammar-guidelines/references/examples/data-set-references) on Data Set References for additional details. Additional formatting rules (from [USC Libraries Research Guides](https://libguides.usc.edu/APA7th/datasets)): - Provide a retrieval date only if the data set is designated to change over time - Date for published data is the year of publication - Date for unpublished data is the year(s) of collection - If version number exists, include in parentheses after the title - If the author and publisher are the same, omit the publisher. - When the webpage you are citing does not indicate a date, use "n.d." instead of the year in both the in-text citations and reference entries. > [!example] >> National Interagency Fire Center. (2019). *Historic_Geomac_Perimeters_Combined_2000_2018*. [Data set]. https://data-nifc.opendata.arcgis.com/datasets/nifc::historic-perimeters-combined-2000-2018-geomac/about > >> Cohen, M. A., & Miller, T. R.  (1991). _Cost of mental health care for victims of crime in the United States_ (ICPSR 6581, Version V1) [Data set].  ICPSR. https://doi.org/10.3886/ICPSR06581.v1 > >> Evans, S. K. (2014).  [Personnel survey] [Unpublished raw data].  University of Southern California. > > ## Wikipedia Click the **View History** tab to access the published on date. >[!example] >2013 Colorado floods. (2022, September 13). In _Wikipedia_. https://en.wikipedia.org/wiki/2013_Colorado_floods ## Webpages Provide the data the articles was published. If unavailable, use the date retrieved. > [!example] > Wasser, L. (2020, September 11). Lesson 1. An Overview of the Cold Springs Wildfire. *Earth Lab*. https://www.earthdatascience.org/courses/use-data-open-source-python/data-stories/cold-springs-wildfire/ > > Climate Nederland - Colorado. (n.d.) *U.S. Climate Data*. Retrieved February 7, 2023, from https://www.usclimatedata.com/climate/nederland/colorado/united-states/usco0652.