When you are reading an article and see a references section near the bottom populated by a series of numbered citations, you might think that if you edit the page, you will see those citations typed in that section and be able to edit them. However, usually what you will see is markup similar to this:
In that case, the text of citations is actually in the body of the article, directly next to the first statements or paragraphs the citations support, using
<ref>...</ref> tags, which display as Footnotes (e.g.) when you are reading an article. The template code shown above in the references section collates and displays all of the citations within the article in a numbered list in which the numbers correspond to the footnote numbers in the text. By clicking on the ^ symbol next to a citation display, you can easily find exactly where in the body of the article the citation text appears in order to edit it. For more, please see Help:Referencing for beginners.