How to cite sources
editArticles can be supported with references in two ways: the provision of general references – books or other sources that support a significant amount of the material in the article – or inline citations, which provide source information for specific statements. Model articles provide general references that support all the content while giving inline citations for statements that are challenged or likely to be challenged. In some articles, where all sources used for the article are cited inline, a separate section for general references will be omitted.
Full citations
editAll citation techniques require detailed full citations to be provided for each source used. They may be formatted by hand or using one of the citation templates. Full citations must contain enough information for other editors to identify the specific published work you used.
Full citations for books typically include: the name of the author, the title of the book or article, and the date of publication. The name of the publisher, city of publication, and ISBN are optional. For journal articles, include volume number, issue number and page numbers. Citations for newspaper articles typically include the title of the article in quotes, the byline (author's name), the name of the newspaper in italics, date of publication, page number(s), and the date you retrieved it if it is online.
For two books by the same author, published the same year, using Harvard referencing, this might be:
- Clancy, T. (1996a). Executive Orders. New York: G.P. Putnam's Sons. ISBN 0-399-14218-5
- Clancy, T. (1996b). Marine. New York: Berkley Books. ISBN 0-425-15454-8
If the article in which the preceding examples appeared used footnotes rather than Harvard citations, the letter after the year would be omitted.
In the Harvard and embedded links citation systems, full citations appear at the end of the article in a section labeled "References." In the footnotes system, full citations may appear in a "References" section or may appear directly in the footnotes.
Citation templates
editVarious citation templates can be used to format full citations. Template for specific formats, such as {{cite book}}, are common. The general {{Citation}} template has additional functionality to support Harvard referencing.
The use of citation templates is neither encouraged nor discouraged by this guideline. Templates may be used at the discretion of individual editors, subject to agreement with the other editors on the article. Some editors find them helpful, arguing that they maintain a consistent and accurate style across articles, while other editors find them annoying, particularly when used inline in the text, because they make the text harder to read in edit mode and therefore harder to edit. Because they are optional, editors should not add templates against consensus.
Inline citations
editInline citations are used to support specific statements in an article. Typically, they should be provided for direct quotes and for statements that are challenged or likely to be challenged. Inline citations may use one of the three systems described below. Please follow the style used by the article's existing citations and do not change the format without checking for objections on the talk page. If there is no agreement, prefer the style used by the first major contributor.
Harvard referencing
editUnder the Harvard referencing system, a book is cited in the text in parentheses, after the section, sentence, or paragraph for which the book was used as a source, using the surname of the author and the year of publication only, with the parentheses closing before the period, as in (Author 2005). These citations can be generated by using inline {{Harvard citation}} templates.
A full citation is then placed at the end of the text in an alphabetized list of "References". If full citations use the {{Citation}} template, the Harvard citation as above will include an automatic link to the full citation. According to The Oxford Style Manual, the Harvard system is the "most commonly used reference method in the physical and social sciences" (Ritter 2002).
Page numbers must be included in a citation that accompanies a specific quotation from, or a paraphrase or reference to, a specific passage of a book or article. They usually follow the date in this way: (Author 2006:28).
In article, common variations:
- For two authors, use (Smith & Jones 2005); for more authors, use (Smith et al. 2005).
- If the same author has published two books in 1996, and both are being referenced in the text, this is written as (Clancy 1996a) and (Clancy 1996b).
- The specific page, section, or division of the cited work should usually follow the date in this way: (Author 2006:28).
- If the date of publication is unavailable, use "n.d." (meaning, no date)
- Newspaper articles may give the name of the newspaper and the date of publication after the sentence (The Guardian, December 17, 2005).
In a "References" section at the end of the article:
For an article: in the case of (Traynor 2005) or (The Guardian, December 17, 2005), this might be:
- Traynor, I. "Judge tells Ankara to decide on fate of leading author", The Guardian, December 17, 2005.
Footnotes
editA footnote is a note placed at the bottom of a page of a document to comment on a part of the main text, or to provide a reference for it, or both. The connection between the relevant text and its footnote is indicated by a number or symbol which appears both after the relevant text and before the footnote.
- Place a <ref> ... </ref> where you want a footnote reference number to appear in an article—type the text of the note between the ref tags.
- Place the <references/> tag in a "Notes" or "References" section near the end of the article—the list of notes will be generated here.
Example:
The Sun is pretty big,<ref>Miller, E: "The Sun", page 23. Academic Press, 2005</ref>
however the Moon is not so big.<ref>Smith, R: "Size of the Moon", ''Scientific American'', 46(78):46</ref>
== References ==
<references/>
Result:
The Sun is pretty big,[1] however the Moon is not so big.[2]
Section headings
editRecommended section names to use for footnotes in Wikipedia are:
- ==Notes==
- ==Footnotes==
- ==References==
Maintaining a separate "References" section in addition to "Notes"
editIt can be helpful when footnotes are used that a separate "References" section also be maintained, in which the sources that were used are listed in alphabetical order. With articles that have lots of footnotes, it can become hard to see after a while exactly which sources have been used, particularly when the footnotes also contain explanatory text. A References section, which lists citations in alphabetical order, helps readers to see at a glance the quality of the references used.
If such a section is included, the footnotes should be in a separate section entitled "Notes" or "Footnotes." Where an alphabetical list of references is provided, "short footnotes" may be used, where the footnotes contain only an author, perhaps title, and page number, without giving a full citation in the footnote itself.
Footnotes come after punctuation
editSome words, phrases or facts must be referenced mid-sentence; footnotes at the end of a sentence or phrase are placed immediately after the punctuation. For example: President Bush called for a halt to the violence,[3] and opposed a timetable for withdrawal.[4]
Notes
edit- footnote examples
Embedded links
editWeb pages referenced in an article can be linked to directly by enclosing the URL in square brackets. For example, a reference to a newspaper article can be embedded like: [http://media.guardian.co.uk/site/story/0,14173,1601858,00.html], which looks like this: [1]
A full citation is also required in a References section at the end of the article.
*Plunkett, John. [http://media.guardian.co.uk/site/story/0,14173,1601858,00.html "Sorrell accuses Murdoch of panic buying"], ''The Guardian'', October 27, 2005. Accessed October 27, 2005.
which appears as:
- Plunkett, John. "Sorrell accuses Murdoch of panic buying", The Guardian, October 27, 2005. Accessed October 27, 2005.
Further reading/External links
editAn ==External links== or ==Further reading== or ==Bibliography== section is placed near the end of an article and offers books, articles, and links to websites related to the topic that might be of interest to the reader. The section "Further reading" may include both online material and material not available online. If all recommended material is online, the section may be titled "External links". Some editors may include both headings in articles, listing only material not available online in the "Further reading" section.
All items used as sources in the article must be listed in the "References" or "Notes" section, and are usually not included in "Further reading" or "External links". However, if an item used as a reference covers the topic beyond the scope of the article, and has significant usefulness beyond verification of the article, you may want to include it here as well. This also makes it easier for users to identify all the major recommended resources on a topic. The Wikipedia guideline for external links that are not used as sources can be found here.
Dealing with citation problems
editUnsourced material
editIf an article has no references, and you are unable to find them yourself, you can tag the article with the template {{Unreferenced}}.
If a particular claim in an article lacks citation and is doubtful, consider placing {{fact}} after the sentence or removing the claim. Consider the following in deciding which action to take:
- If it is doubtful but not harmful to the whole article, use the {{fact}} tag to ask for source verification, but remember to go back and remove the claim if no source is produced within a reasonable time.
- If it is doubtful and harmful, you should remove it from the article; you may want to move it to the talk page and ask for a source, unless you regard it is as very harmful or absurd, in which case it should not be posted to a talk page either. Use your common sense. Do not be inappropriately cautious about removing unsourced material; it is better for Wikipedia to say nothing on an issue than to present false or misleading material.
All unsourced and poorly sourced contentious material about living persons should be removed from articles and talk pages immediately. It should not be tagged. See Wikipedia:Biographies of living persons and Wikipedia:Libel.
What to do when a reference link "goes dead"
edit, WebCite
When a link in the References section or Notes section (a link to a source for information in the article) "goes dead", it should be repaired or replaced if possible, but not deleted. External links/Further reading sections are not as important, but bad links in those sections should also be fixed. Often, a live substitute link can be found. In most cases, one of the following approaches will preserve an acceptable citation:
- Some pages can be recovered from the Internet Archive or WebCite. Just go to http://www.archive.org/ or http://www.webcitation.org, respectively, and search for the old link by URL. Make sure that your new citation mentions the date the page was archived by the Internet Archive. In case of WebCite, any broken URL can be searched for and replaced using the format http://www.webcitation.org/query?url=URL&date=DATE, where URL is the URL that is broken and needs to be restored. The DATE variable is optional and indicates the (approximate) caching date. For example, http://www.webcitation.org/query?url=www.pewinternet.org/pdfs/PIP_Health_Report_July_2003.pdf&date=2005-12-31 retrieves a copy of the URL http://www.pewinternet.org/pdfs/PIP_Health_Report_July_2003.pdf which is closest to the date of Dec 31st, 2005 (in this example the actual caching date was 21 days before the requested date). WebCite allows on-demand prospective archiving and is not crawler-based, i.e. pages are only archived if the author has requested archiving when he cited the piece for the first time, which is highly recommended
- If this was a non-blind citation of web-only material, it may be worth the effort to search the target site for an equivalent page at a new location, an indication that the whole site has moved, etc.
- If the link was merely a "convenience link" to an online copy of material that originally appeared in print, and an appropriate substitute cannot be found, it is acceptable to drop the link but keep the citation.
- If you cannot find the page on the Internet Archive, remember that you can often find recently deleted pages in Google's cache. They will not be there long, and it is no use linking to them, but this may let you find the content, which can be useful in finding an equivalent page elsewhere on the Internet and linking to that.
If none of those strategies succeed, do not remove the inactive reference, but rather record the date that the original link was found to be inactive — even inactive, it still records the sources that were used, and it is possible hard copies of such references may exist, or alternatively that the page will turn up in the near future in the Internet Archive, which deliberately lags by six months or more. When printed sources become outdated, scholars still routinely cite those works when referenced.