Ensure that you can document all of the elements of your citation. You will need the author's name and the title of the chapter/article or book, as well as the title of the book/journal/magazine if your cited source is an article. You will also need the place of your source's publication, the date of its publication, and the page or pages on which the information that you have cited appears. Any elements that are unavailable can be substituted with abbreviations that are specific to your style guide.
Create the space for the footnote. If you are using a word processor, this can be done by moving your cursor to the point where you want your footnote to appear, clicking on "Insert" from the command menu, and then clicking on "Footnote" and pressing "Enter" or clicking "OK."
Add the author's name, with the given name appearing first and the surname last. Then supply the title of the article, bracketed by quotation marks. Then indicate the title, italicized, of the book in which the article is found. Make sure that each element is separated by a comma. The comma after the article title is placed within the closing quotation mark. If you are merely citing the book and not an article in it, then skip the addition of the article title in this step.
Add the names of the editor or editors, with given name appearing first and surname last, and the full name preceded by the abbreviation "ed." for a single editor or "eds" for multiple editors. Then give the page number or numbers on which the information that you are citing can be found. Again, ensure that each element is separated by a comma. Leave no comma after the page number or numbers. If you are merely citing the book and not an article in it, then skip the insertion of the page numbers in this step.
Add, after typing an open parenthesis, the place of publication followed by the publisher -- with these two elements separated by a colon -- and finally the date of publication, separated from the publisher's name by a comma and a space. Type a closing parenthesis.
End the citation by placing a period outside of the last parenthesis.
Check to make sure that your citation looks like this example if you are citing an article:
Monika Otter, "Functions of fiction in historical writing," Writing Medieval History, ed. Nancy Partner, 110-111 (London: Hodder Arnold, 2005).
Or like this example if you are citing only the book:
Writing Medieval History, ed. Nancy Partner, (London: Hodder Arnold, 2005).