Question

Which citation number should be used for the same source, if repeated

Answer 1

Which citation number should be used for the same source, if repeated:

This depends on how you are citing them. If you are citing them in-text more than once, and you are referring to the same source each time, then you can simply reuse that same in-text reference with a single entry on your references page at the end.

If you are citing the same author, but from different sources, you may have to follow different rules. Let's say you are citing an author named Jane Doe three times. If each of her articles or books are published in different years, then you don't need to do anything different than you normally would. Let's say she published articles in 2009, 2011, and 2012. Then each entry would just be (Doe, 2009), (Doe, 2011), and (Doe, 2012).

If, on the other hand, all of her articles were published in the same year, then you would need to add letters to differentiate between them. Let's say they were all published in 2009. So then it would be (Doe, 2009a), (Doe, 2009b), and (Doe, 2009c). In your reference list you should then add the corresponding letters.

Consecutive references:

When you are referencing the same source in two (or more) footnotes the second and subsequent references should be entered as "Ibid." and the page number for the relevant footnote. Use "Ibid." without any page number if the page is the same as the previous reference.

Example footnotes:

1. Stephen Marshall, Cities, Design and Evolution (Abingdon, U.K.: Routledge, 2009), 69.

2. Ibid., 72.

Nonconsecutive references:

When referring to a previously cited work, but with other references intervening, use a shortened reference. This is only the author's/editor's last name and a shortened form of the title. Titles of four or less words are not shortened.

Example footnotes:

1. Stephen Marshall, Cities, Design and Evolution (Abingdon, U.K.: Routledge, 2009), 69.

2. Deidre Brown, Maori Architecture: From Fale to Wharenui and Beyond (Auckland, N.Z.: Raupo, 2009), 56.

3. Marshall, Cities, Design, 72.

Several books by the same author in the bibliography:
Where your bibliography contains two or more works by the same author entries are arranged alphabetically by title (leading definite/indefinite articles being ignored) under the author's name. The author's name is replaced in the second and subsequent entries by six hyphens:

Jencks, Charles and Edwin Heathcote. The Architecture of Hope: Maggie's Cancer Caring Centres. London: Frances Lincoln, 2010.

------. Can Architecture Affect Your Health? Arnhem, The Netherlands: Sikkens Foundation and ArtEZ Press, 2012.

------. The Scottish Parliament. London: Scala Publishers, 2005.