Editing Incubator escapee wiki:Citing sources (section)

===Links and ID numbers===
A citation ideally includes a link or ID number to help editors locate the source. If you have a URL (web page) link, you can add it to the title part of the citation, so that when you add the citation to Wikipedia the URL becomes hidden and the title becomes clickable. To do this, enclose the URL and the title in square brackets—the URL first, then a space, then the title. For example:
<syntaxhighlight lang="moin">''[https://monographs.iarc.fr/ENG/Monographs/vol66/mono66-7.pdf IARC Monographs On The Evaluation Of Carcinogenic Risks To Humans – Doxefazepam]''. International Agency For Research On Cancer (IARC). 66: 97–104. 13–20 February 1996.</syntaxhighlight>
For web-only sources with no publication date, the "Retrieved" date (or the date you accessed the web page) should be included, in case the web page changes in the future. For example: {{xt|Retrieved 15 July 2011}} or you can use the [[Wikipedia:RefToolbar 2.0#Automatic date insertion|access-date]] parameter in the automatic [[Wikipedia:refToolbar 2.0]] editing window feature.

You can also add an ID number to the end of a citation. The ID number might be an [[ISBN]] for a book, a [[Digital object identifier|DOI]] (digital object identifier) for an article or some e-books, or any of several ID numbers that are specific to particular article databases, such as a PMID number for articles on [[PubMed]]. It may be possible to format these so that they are automatically activated and become clickable when added to Wikipedia, for example by typing ISBN (or PMID) followed by a space and the ID number.

If your source is [[Wikipedia:Offline sources|not available online]], it should be available in reputable libraries, archives, or collections. If a citation without an external link is challenged as unavailable, any of the following is sufficient to show the material to be reasonably available (though not necessarily [[Wikipedia:Verifiability#Reliable sources|reliable]]): providing an [[ISBN]] or [[OCLC]] number; linking to an established Wikipedia article about the source (the work, its author, or its publisher); or directly quoting the material on the talk page, [[WP:COPYVIO|briefly]] and in context.

====Linking to pages in PDF files====
{{anchor|PDF|pdf}}
{{shortcut|WP:PAGELINKS|WP:BOOKLINKS}}

Links to long PDF documents can be made more convenient by taking readers to a specific page with the addition of <code>#page=<var>n</var></code> to the document URL, where <code>n</code> is the page number. For example, using <code><nowiki>https://www.domain.com/document.pdf#page=5</nowiki></code> as the citation URL displays page five of the document in any PDF viewer that supports this feature. If the viewer or browser does not support it, it will display the first page instead.

====Linking to Google Books pages====
{{shortcut|WP:GBOOKS}}
{{further information|Wikipedia:Google Books and Wikipedia}}
[[Google Books]] sometimes allows numbered book pages to be linked to directly.
Page links should only be added when the book is available for preview; they will not work with snippet view. Keep in mind that availability varies by location. No editor is required to add page links, but if another editor adds them, they should not be removed without cause; see the [[Wikipedia_talk:Citing_sources/Archive_30#Linking_to_Google_Books_pages|October 2010 RfC]] for further information.

These can be added in several ways (with and without citation templates):
*Rawls, John. [https://books.google.com/books?id=kvpby7HtAe0C&pg=PA18 ''A Theory of Justice'']. Harvard University Press, 1971, p. 18.
*Or with a template: {{cite book |last=Rawls |first=John |title=A Theory of Justice |publisher=Harvard University Press |date=1971 |page=18 |url=https://books.google.com/books?id=kvpby7HtAe0C&pg=PA18}}
*[https://books.google.com/books?id=kvpby7HtAe0C&pg=PA18 Rawls 1971, p. 18].
*[https://books.google.com/books?id=kvpby7HtAe0C&pg=PA18 Rawls 1971], p. 18.
*Rawls 1971, [https://books.google.com/books?id=kvpby7HtAe0C&pg=PA18 p. 18].
*Rawls 1971, [https://books.google.com/books?id=kvpby7HtAe0C&pg=PA18 18].

In edit mode, the URL for p. 18 of ''[[A Theory of Justice]]'' can be entered like this using the {{tl|Cite book}} template:

<syntaxhighlight lang="wikitext">{{cite book |last=Rawls |first=John |date=1971 |title=A Theory of Justice |url=https://books.google.com/books?id=kvpby7HtAe0C&pg=PA18 |publisher=Harvard University Press |page=18}}</syntaxhighlight>

or like this, in the first of the above examples, formatted manually:
<syntaxhighlight lang="wikitext">Rawls, John. [https://books.google.com/books?id=kvpby7HtAe0C&pg=PA18 ''A Theory of Justice'']. Harvard University Press, 1971, p. 18.</syntaxhighlight>

When the page number is a [[Roman numeral]], commonly seen at the beginning of books, the URL looks like this for [https://books.google.com/books?id=kvpby7HtAe0C&pg=PR17 page xvii] (Roman numeral 17) of the same book:<br />

{{in5}}<code><nowiki>https://books.google.com/books?id=kvpby7HtAe0C&pg=PR17</nowiki></code><br />

The <samp>&pg=PR17</samp> indicates "page, Roman, 17", in contrast to the <samp>&pg=PA18</samp>, "page, [[Arabic numeral|Arabic]], 18" the URL given earlier.

You can also link to a [[tipped-in page]], such as an unnumbered page of images between two regular pages. (If the page contains an image that is protected by copyright, it will be replaced by a tiny notice saying "copyrighted image".) The URL for [https://books.google.com/books?id=dBs4CO1DsF4C&pg=PA304-IA11 eleventh tipped-in page inserted after page 304] of ''The Selected Papers of Elizabeth Cady Stanton and Susan B. Anthony'', looks like this:<br />

{{in5}}<code><nowiki>https://books.google.com/books?id=dBs4CO1DsF4C&pg=PA304-IA11</nowiki></code><br />

The <samp>&pg=PA304-IA11</samp> can be interpreted as "page, Arabic, 304; inserted after: 11".

Note that some templates properly support links only in parameters specifically designed to hold URLs like {{para|url}} and {{para|archive-url}} and that placing links in other parameters may not link properly or will cause mangled [[COinS]] metadata output. However, the {{para|page}} and {{para|pages}} parameters of all {{cs1}}/{{cs2}} citation templates, the family of {{tl|sfn}}- and {{tl|harv}}-style templates, as well as {{tl|r}}, {{tl|rp}} and {{tl|ran}} are designed to be safe in this regard as well.

[https://citer.toolforge.org/ Citer] may be helpful.

Users may also link the quotation on Google Books to individual titles, via a short [[permalink]] which ends with their related ISBN, [[OCLC]] or [[Library of Congress Control Number|LCCN]] numerical code, e.g.:
<code><nowiki>https://books.google.com/books?vid=ISBN0521349931</nowiki></code>, a permalink to the Google book with the [[International Standard Book Number|ISBN]] code 0521349931.
For further details, you may see [https://support.google.com/books/partner/answer/3474239?hl=en/ How-to explanation] on support.google.com.