The <a href="https://en.wikipedia.org/wiki/Treaty_of_Lisbon" id="mwAYU" rel="mw:WikiLink" title="Treaty of Lisbon">Treaty of Lisbon</a> entered into force in the <a href="https://en.wikipedia.org/wiki/European_Union" id="mwAYY" rel="mw:WikiLink" title="European Union">European Union</a>.<sup about="#mwt137" class="mw-ref reference" data-mw='{"name":"ref","attrs":{"name":""},"body":{"id":"mw-reference-text-cite_note-28"}}' id="cite_ref-28" rel="dc:references" typeof="mw:Extension/ref"><a href="./December_1#cite_note-28" id="mwAYc" style="counter-reset: mw-Ref 28;"><span class="mw-reflink-text" id="mwAYg">[28]</span></a></sup>
<span class="mw-reference-text" id="mw-reference-text-cite_note-28"><a class="external text" href="http://eur-lex.europa.eu/legal-content/EN/TXT/?uri=OJ:C:2008:115:TOC" id="mwCLE" rel="mw:ExtLink nofollow">eur-lex.europa.eu: " Official Journal of the European Union</a>, <a about="#mwt134" class="mw-redirect" href="./ISSN_(identifier)" id="mwCLM" rel="mw:WikiLink" title="ISSN (identifier)">ISSN</a><span about="#mwt134" id="mwCLQ" typeof="mw:Entity"> </span><a about="#mwt134" class="external text" href="https://www.worldcat.org/search?fq=x0:jrnl&amp;q=n2:1725-2423" id="mwCLU" rel="mw:ExtLink nofollow">1725-2423</a> C 115 Volume 51, 9 May 2008, retrieved 1 June 2014</span>