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Research: Chicago Referencing Style: Chicago style with notes and bibliography

Chicago is a referencing system that uses a noting technique. This guide is intended for IB Diploma Programme students.

Note to Extended Essay candidates:

  • The information below (in this box) gives advice about creating your citations with a bibliography using the Chicago style.
  • For IB Diploma students who have already created footnoted references, but now need to add a bibliography (as this is mentioned in the IB Extended Essay Guide and/or your supervisor asks you to do so), then the notes below require you to change some references in text.
  • If you do not have much time left, please see the box at the bottom of this page. 

Notes with bibliography

Although the technique - whether you use footnotes or endnotes - is similar, there are differences when you use a bibliography in Chicago style. (If you're required to cite in footnotes and provide a bibliography, then you need to look at the tab about using Chicago with footnotes AND this page.)

When you use a source of information, you signify this in your text by using a number, starting with 1, at the end of the sentence (or clause of a longer sentence) in which the source of information is used. 

When you quote someone, the note number appears immediately after the quote, e.g. "the solution thickened and turned purple."¹

The marker in the text, i.e. the number in superscript, e.g. ¹, is the same as endnoting and footnoting technique. (Remember, there should be a footnoting option in the Word document you're using.)

These (above) are all the same as for footnotes or endnote technique, as explained on the previous tabs. 

The note appears at the foot or bottom of the same page as that in which you refer to the source of information, but now you only need give brief details, as the full details are given in the bibliography. 

In the footnote, an entry should appear in a similar format to this example (for a book):

   1. Cottrell, The Study Skills Handbook, 45. 

In this example, the number is in regular font size; the author's surname or family name only appears next, followed by the title (in italics), with the page number given last. 

This is another example, this time of a website:

   2. National Environment Agency, "PSI Readings". 

For an interview you carry out, the note details should be similar to this example:

   3. Chen, interview.

If you use a source consecutively, you need to use separate numbers. When this happens, you can use the abbreviation '"Ibid", which simply means that it is the same source as the last footnote entry. 

A big difference comes in the bibliography. This is where all the relevant details about a source of information are given. The bibliography is provided at the end of your work. 

Using the examples above, this is the style in which they should appear in the bibliography:

Cottrell, Stella. The Study Skills Handbook. London: Palgrave Macmillan, 2008. 

In this example, there is no number; the author's surname appears next, followed by a comma and the first name, then the title (in italics), followed by a full-stop or period. Then the place of publication, followed by a colon, i.e. :, then publisher, and finally date (year) of publication. 

This is another example of a bibliography entry, this time of a website:

National Environment Agency, "PSI Readings", Singapore Government,  accessed March 26, 2014, 

For an interview you carry out, the bibliography entry should be similar to this example:

Chen, Martin. (Managing Director, InfoSpace Ltd.) Interview with the author. May 2013.

What to check before submitting your work

The bibliography appears at the end of the essay.

The bibliography should be in one alphabethical list, ordered by the surname or family name of the author of the source of information.

Remember that in a bibliography, the family or surname of the author is listed first, followed by a comma and the first name of a person.

If the author is an organization, it is listed in full, e.g. World Health Organization, or Royal Shakespeare Company. 

The heading you use should be either Bibliography or References. 

Page numbers are not given in the bibliography entry. Page numbers are only given in the footnote itself. 

Need to add a bibliography at the very last minute?

If you find you need (or are asked to) add a bibliography to your Extended Essay draft at the last minute, and are not prepared or want to change the footnoted references in your text, to make it consistent with using Chicago style with a bibliography, then reproduce the list of references in one alphabetical order according to the family or last name (or surname) for the bibliography. 

In other words, you keep the references in the footnotes as they are, but you're simply adding a bibliography at the end as well.

Remember, though, in a bibliography, you only list a source of reference once. If alphabeticising your list of references, you may need to delete text/entries where, for instance, you've used a source of information twice or more. 

If you use an online generator to organize your references, this online service might be able to do this for you. If you're just using a free service on the Internet, check that you can do this in Chicago. Some free services only let you use one style, which might not be Chicago. Don't forget, if you set up EasyBib through the College website, the College pays for the subscription model, so you get the option to use Chicago (and other referencing styles).