Wikipedia:IC

Inline citations are often placed at the end of a sentence or paragraph. Inline citations may refer to electronic and print references such as books, magazines, encyclopedias, dictionaries and Internet pages. Regardless of what types of sources are used, they should be reliable; that is, credible published materials with a reliable publication process whose authors are generally regarded as trustworthy or authoritative in relation to the subject at hand. Verifiable source citations render the information in an article credible to researchers.

Parenthetical referencing is a citation system in which in-text citations are made using parentheses. Various formats are seen, e.g. (Author, date) or (Author, date:page), etc. Such citations are normally typed in plain text and appear before punctuation. The full bibliographic citation is then typed at the bottom of the article, usually in alphabetical order.

If multiple citations for the same source are included in the article, and you are using <ref> tags, you can name the footnote to link to the same note repeatedly. To do this, add name="X" to the first <ref> tag, so that it looks like this: <ref name="X">. As before, this will generate a number at the end of the sentence. Replace the "X" with any word to denote which source the computer should jump to when multi-linking like this. Notice that this method of citing creates the same number for each entry cited with a <ref name="X"> citation. You can reuse the footnote repeatedly merely by typing the named <ref> tag with a slash following the name, like this: <ref name="X" />

This is an older citation method which is still sometimes used for citations and/or for explanatory text. This template creates superscript numbers in a text which, when clicked on, direct the reader to the citation at the bottom of the page.

Both the reference template and the note template consist of two parts: {{|word reference}} and {{|word reference}}. If you wish to use these templates then begin by placing the {{| }} template in the article where you wish to cite the presented information. After the "|" include a small word reference for the citation; this will tell the computer which link it should jump to when a reader clicks on the article citation.

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Wikipedia