A new <a href="https://en.wikipedia.org/wiki/Mexico" id="mwAcY" rel="mw:WikiLink" title="Mexico">Mexican</a> oil legislation goes into effect, leading to the formal outbreak of the <a href="https://en.wikipedia.org/wiki/Cristero_War" id="mwAcc" rel="mw:WikiLink" title="Cristero War">Cristero War</a>.<sup about="#mwt280" class="mw-ref reference" data-mw='{"name":"ref","attrs":{},"body":{"id":"mw-reference-text-cite_note-54"}}' id="cite_ref-54" rel="dc:references" typeof="mw:Extension/ref"><a href="./January_1#cite_note-54" id="mwAcg" style="counter-reset: mw-Ref 54;"><span class="mw-reflink-text" id="mwAck">[54]</span></a></sup>
<span class="mw-reference-text reference-text" id="mw-reference-text-cite_note-54"><cite about="#mwt277" class="citation book cs1" id="CITEREFGruening1929"><a href="./Ernest_Gruening" id="mwDqo" rel="mw:WikiLink" title="Ernest Gruening">Gruening, Ernest</a> (1929). <a class="external text" href="https://books.google.com/books?id=IzELAAAAYAAJ" id="mwDqs" rel="mw:ExtLink nofollow"><i id="mwDqw">Mexico and Its Heritage</i></a>. Century Company.</cite><span about="#mwt277" class="Z3988" id="mwDq0" title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&amp;rft.genre=book&amp;rft.btitle=Mexico+and+Its+Heritage&amp;rft.pub=Century+Company&amp;rft.date=1929&amp;rft.aulast=Gruening&amp;rft.aufirst=Ernest&amp;rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DIzELAAAAYAAJ&amp;rfr_id=info%3Asid%2Fen.wikipedia.org%3AJanuary+1"></span></span>