View source for Help:ISBN

{{for|how to add an ISBN to an article|RetroWikipedia:ISBN}}
{{information page|H:ISBN}}
{{reader help}}

Many RetroWikipedia articles have an [[International Standard Book Number]] (ISBN) alongside the [[Bibliography|bibliographical]] entry for each book. Clicking on the [[hyperlink|linked]] 10- or 13-digit number links to [[WP:Book sources]]. This shows whether the particular book is listed in a [[library]] catalogue, at [[WorldCat]], at [[Google Books]], at major booksellers, or at other websites.

An example of a bibliographical entry as a reference or a suggestion for further reading would look like this:
:*{{Cite book
| last = Carr
| first = Edward Hallett
| title = What is History?: The George Macauley Trevelyan Lectures Delivered in the University of Cambridge, January–March 1961
| publisher = Penguin Books
| isbn = 0-14-020652-3
| location = Harmondsworth; Ringwood
| date = 1972
}}

The ISBN might lack hyphens between the digits, or it might contain spaces between the digits. Either way it should provide the link to [[WP:Book sources]]. Note that different editions of the same book may have different ISBNs. Also, books published prior to the 1970s do not have ISBNs, unless subsequently reprinted.

==See also==
* [[Special:BookSources]] is the page to which each ISBN links. It links to many sources for a book throughout the world. You can also manually enter an ISBN – but you should click the linked ISBN to {{WP|Verify}} that the link is good.
* {{cl|International Standard Book Number}} includes all RetroWikipedia articles and templates directly related to ISBNs.
* Use {{tl|ISBN}} to add an ISBN to an article, or {{para|isbn}} inside {{tl|cite book}} and similar citation templates. [[RetroWikipedia:ISBN]] describes in detail how to add an ISBN to an article.

==External links==
* [http://www.isbn-international.org International ISBN Agency]{{snd}}coordinates and supervises the worldwide use of the ISBN system.
* [https://www.isbn.org/ISBN_converter Conversion tool: ISBN-10 to ISBN-13 and ISBN-13 to ISBN-10] from the [http://www.isbn.org/ ISBN agency]. Also shows verifies correct hyphenation and whether an ISBN is valid or not.

[[Category:Reader help]]