Subsequent Citations – The Shortcuts

After a source has been cited in full, and you wish to cite it again in another footnote or endnote, it is not necessary to provide another full bibliographic entry. You may simplify the entry in one of two ways, depending upon the timing.

1. If you wish to cite a source two or more times in immediate succession, you may substitute the term “Ibid.” for the full entry. “Ibid.” is an acronym for the Latin adverb “ibidem,” meaning “in the same place.” This indicates to the reader that you are citing the same source again, and obviates the need for making laborious and time-consuming citations. You need only add the correct page number or numbers if the subsequent citation was found in another part of the source. If the citation was found on the same page as the previous one, simply enter “Ibid.” Footnotes or endnotes featuring these entries would look like this, where citation #7 is the first citation of the source:

7 Stanley Karnow, Vietnam – A History: The First Complete Account of Vietnam at War (New York, NY: Penguin Books, 1983) 169.
8 Ibid.
9 Ibid. 172.
10 Ibid. 174-175.

2. Secondly, if you wish to cite a source again later, and there are citations from other sources in between, then you may shorten the entry to the author’s last name alone, followed by the term “op. cit.” This is an abbreviation for the Latin term “opere citato,” meaning “in the work cited.” This method indicates to the reader that you are returning to cite a source consulted previously – but not immediately beforehand. Note: If you are using two or more sources by the same author, you will need to indicate more clearly to which source you are referring, generally by the inclusion of the date of publication. This will keep the sources distinct. Remember to provide a full bibliographic entry the first time you cite each source. Footnotes or endnotes featuring these entries would look like this:

7 Stanley Karnow, Vietnam – A History: The First Complete Account of Vietnam at War (New York, NY: Penguin Books, 1983) 169.
8 Daqing Yang, “A Sino-Japanese Controversy: The Nanjing Atrocity as History,” Sino-Japanese Studies 3. 1. (1990): 31.
9 Stanley Karnow, op. cit. 172.
10 Ibid. 177.
11 Ibid.
12 Daqing Yang, op. cit. 31.
13 Ibid.

As you can see, these two shortcuts can be used in combination. Each time, be certain that “Ibid.” is used only when a source is cited two or more times in immediate succession, otherwise your citations will be incorrect. If you are careful, this method of citation will save time.