Some general rules for formatting footnotes:
The first time you cite a source, you will need to include the full citation information. Each subsequent time you cite it in the same paper, however, you will use a short form citation.
If you are citing only one work by a particular author, use only their name and the page number.
4. Michael Davis, Street Gang: The Complete History of Sesame Street (New York: Viking, 2008), 43.
5. Davis, 102.
If you are citing multiple works by the same author, use the author's name, a shortened (but clear!) version of the title, and the page number.
12. Davis, Street Gang, 197.
If you are citing a work which does not have an author or editor, use a shortened (but clear!) version of the title and the page number.
18. Driving Home, 280.
Ibid, which comes from the Latin ibidem or "in the same place", is used to cite a work whose bibliographic data appears in the note directly preceding it. If the citation information is exactly the same, including the page number, simply use 'Ibid.'. If the citation is the same save for the page number, use 'Ibid., #'.
Note that because Ibid. is an abbreviation, it should be followed by a period.
23. Davis, Street Gang, 197.
24. Ibid., 213