It is critical that one work, when cited in several languages, be treated as a single citation, clearly identified as one citation, and referenced as one from within the document, so that the number of cited objects is not multiplied. It is important to note that:

There are two basic approaches to tagging a citation (<mixed-citation> or <element-citation>) in more than one language:

• Perhaps the simplest way is to create two or more same-content but different-language citations inside a <citation-alternatives> element that is inside a bibliographic reference (<ref>). For a more complete description, see Citations in Multiple Languages.
• It is slightly more complex but also possible to mix elements from several languages inside a single citation element. See below.

To allow multiple languages within one citation element, the @xml:lang attribute may be used freely on the component elements within a citation to indicate the language of the component. The multi-language attributes may be used to declare that these components (multiple <article-title>s, for example) are all the same piece of information. (For more details concerning the multi-language attribute, see Citations in Multiple Languages.)

Ways to handle multiple same-content, different-language elements inside a citation element include:

• A contributor name in more than one language should be placed inside a <name-alternatives> grouping element. This ensures that one author does not get cited multiple times for a single article. All the named alternatives in such a grouping represent the same author. Each <name> inside the <name-alternatives> should use the @xml:lang attribute to identify the language of the name.
• An <article-title> in more than one language should repeat the <article-title> element for the second (and subsequent) titles with an @xml:lang attribute. The @lang-group should be used to state that the two title elements represent a single title. (Note: The element <trans-title> has been deprecated, was preserved only for backward compatibility purposes, and should not be used to hold alternative language titles.)
• A <source> in more than one language should repeat the element <source> with an @xml:lang attribute. The @lang-group should be used to state that the two title <source>s represent a single source. (Note: The element <trans-source> has been deprecated, was preserved only for backward compatibility purposes, and should not be used to hold alternative language sources.)
• Other elements within a citation that are present in more than one language should use the @xml:lang attribute on each element to mark the language of each component. The @lang-group should be used to state that the two or more components represent a single real world entity.