Chemistry

For every in-text citation that you include in your assignment, you need to have a corresponding full citation on the References page. Similarly, every citation entry on your References page should represent at least one in-text citation. It is easiest to collect the full citation information for every resource that you find while doing your research, then drop the ones that you use into the References page as you use information from them in your narrative, as it can be very challenging if you wait to build your full citations while writing your paper!

• Basic format of page
  • Begin the Reference list on a new page immediately after the body of your text. It is the last page in your paper unless you have appendices or an index.
  • The word “References” in bold is centered at the top of the page.
  • Double space the entire list.
  • Each entry provides Author, Date, Title, and Source of the work being cited.  See the details section below for more information!
  • Entries are ordered alphabetically by Author.  
  • The first line of each entry is left justified with every subsequent line of the entry indented by 1/2".

Visit Purdue's OWL to see a sample APA paper including a References page; another example to help you visualize the format for a References page is shown here in a graphic by Jennifer Betts of Bibliography.com (2021):

A full citation for the References page of an APA work will include 4 basic elements separated with periods: Author. (Date). Title. Source. For additional information, the APA also a concise guide for full citations of journal articles, books, and book chapters, as well as an extensive list of example reference citations for various circumstances.

• Author may be a person, many people, or an organization.
  • Basic format is Last, F. M. = “Lastname, First initial. Middle initial.”
    • Example: Smythe, G. B. (Date). Title. Source.
    • International Association of Smythe Families. (Date). Title. Source.
  • Multiple Authors
    • Every author of a work is listed in the Reference citation using the basic format, separated by a comma between each author and with an ampersand (“&” symbol) before the last author’s name; you must list the first 20 authors this way, but if there are more than 20 authors, you show the first 20 (with no ampersand) followed by an ellipse (“…” symbol). Author names are shown in the same order as they appear in the publication.
    • Example: Smythe, G. B. & Jonas, L. (Date). Title. Source.
    • Example: Smythe, G., Smythe, L., Smythe, N. & Smythe, R. (Date). Title. Source.
  • If an Author has multiple entries, list them in order from oldest to most recent.
  • If an Author/s have multiple entries in the same year, add a letter to the years to differentiate between publications; use that designation for in-text citations throughout you narrative.
    • Example: Author. (2021a). Title. Source.
  • No Author
    • Use the title of the work in place of an unknown Author
    • Example: Yearbook of the International Association of Smythe Families. (Date). Source.
• Dates can take many forms depending on the resource being cited; check guidelines for each type of resource to make sure you include the right information in the correct order.
  • Basic format is to place the Date in parentheses with a period after the closing bracket.
    • Example: Author. (2021). Title. Source.
  • Books
    • Use the copyright year.
    • Example: Author. (2021). Title. Source.
  • Journal articles
    • Use the date from the Journal volume in which article appears, even if it's different than the copyright year. Include only the year for the Date element; the full date of the journal is part of the Source element.
    • Example: Author. (2021). Title. Source.
  • Webpages
    • Do not assume the copyright date from the site's footer applies to the content that you are citing!
    • If you can find the date the content was posted or updated, use that date, otherwise treat the content as having no date (as specified below).
      • Example: Author. (2021, January 1). Title. URLincludinghttp://
      • Example with no date, retrieval date included: Author. (n.d.). Title. Source. Retrieved January 1, 2021, from URLincludinghttp://
  • Reference resources (e.g. an Encyclopedia)
    • Use the month, day, or season along with the year
    • Basic format: (year, month/day). Or (year, season).
      • Example: Author. (2021, Spring/Summer). Title. Source.
      • Example: Author. (2021, January 1). Title. Source.
  • No Date
    • Include a complete date when possible; if you can't find all of the date elements for the resource type, include as much information in the date element as you can find. If there is absolutely no date associated with the resource, then you use an abbreviation for "no date" in place of the date element. Use lower case letters with a period behind each letter and no spaces: (n.d.).
• Title format changes depending on whether you are citing part of a larger work or if the citation is for a whole, stand-alone work.
  • Title for parts of a work.
    • Use the title of the article or chapter as the Title element; the title of the whole work is included in the Source.
    • Includes journal and Newspaper articles, book chapters, etc.
    • Basic format is to use normal text (no quotes, italics, etc.) expressed in sentence case (i.e. only capitalize the first word, the first word after a colon or dash, and proper nouns).
  • Title for a whole work
    • Includes books, reports, etc.
    • Basic format is to italicize the Title and to use sentence case (i.e. only capitalize the first word, the first word after a colon or dash, and proper nouns).
    • Use the title of the work is the Title element.
      • Example: Author. (Date). This is the title: This is the subtitle. Source.
    • Include in parentheses at the end of the Title any information necessary to retrieve the resource (e.g. edition or volume number).  The period that ‘closes’ the Title element goes after the closing bracket.
      • Example: Author. (Date). This is the title (2^nd ed., Vol. 7). Source.
• Source elements tell the reader where the resource can be found.
  • Basic format of the Source includes one or two parts depending on whether the work is accessed digitally.
    • The first part is a necessary element for all Sources; this is the publication information of the book (publisher) or the periodical (i.e. name of journal, volume and issue numbers, and page range of the article).
    • The second part, required when the work was accessed digitally, is the URL (web address or permalink as appropriate) or its DOI (Digital Object Identifier) which is a unique id permanently assigned to that object.
  • Source information that has already been used elsewhere in the reference citation may be eliminated.
    • If the Title was used in place of the Author element, you skip the Title element.
  • If you cited part of a resource
    • If you cited part of a book for the Title (e.g. a book chapter or encyclopedia entry), the whole work is the Source.
    • If the resource has an editor, the Source entry will have the include the editor’s name/s, the Source’s italicized title, and the page range for the part that you cited in parentheses, followed by a period, then the name of the publisher’s name as it’s shown in the work. Finish with the URL/DOI if available.
      • Example: Author. (Date). Title. In F. M. Last (Ed.), This is the title for the whole book (pp. 101-142). Publisher. DOIorURLincludinghttp://
      • Example: Author. (Date). Title. In F. M. Last and F. M. Last (Eds.), This is the title for the whole book (p. 474). Publisher. DOIorURLincludinghttp://
      • If the editor’s name/s have already been used in the Author field, don’t repeat them in the Source; use “In This is the title…).
  • If you cited the whole work
    • If the identifying information for the work has already appeared in the Title of the citation entry, there’s no need to repeat it in the Source. The Source portion of the citation for a whole work therefore includes only the publisher and the URL or DOI for the work.
      • Example: Author. (Date). Title of the whole work. Publisher. DOIorURLincludinghttp://
  • Periodicals
    • Basic format is to use the title as shown by the publisher including capitalization, abbreviations, and punctuation and italicize the journal title. Use an unitalicized comma then enter the volume number of the journal which is italicized. If there is an issue number include it in parentheses after the volume number; do not italicize the parenthetical portion of the information. Use an unitalicized comma, then put the page range/s followed by a period, then include the URL/DOI.
      • Example: Author. (Date). Title. Journal Title, 42(1), 18-24. DOIorURLincludinghttp://
    • If an online publication of a periodical is missing some of the information shown above, simply put the elements that are available.
      • Example: Author. (Date). Title. The Washington Post. URLincludinghttp://
  • A few notes on electronic retrieval of research resources:
    • You do not include any information on the database in which you found the resource unless that exact database is the only place for your reader to retrieve the work!
    • The URL or DOI in your Reference list should begin with http:// and they should be active links if your work is available online. You can use the default settings for active links (e.g. underlined blue text) or the links can be black without underlining.

American Psychological Association. (2020). Publication manual of the American Psychological Association: The official guide to APA style (7th edition). 

Betts, J. (2021, March 17). APA Citation Generator (Free) & Complete APA Format Guide. Bibliography.com. https://www.bibliography.com/apa/apa-format-and-citations/

Purdue OWL. (n.d.). APA Sample Paper. Purdue Writing Lab. https://owl.purdue.edu/owl/research_and_citation/apa_style/apa_formatting_and_style_guide/apa_sample_paper.html