<?xml version="1.0" encoding="UTF-8"?>
<XML><RECORDS>
<RECORD>
	<REFERENCE_TYPE>31</REFERENCE_TYPE>
	<AUTHORS>
		<AUTHOR>Javier Almeida, M.A. Martin-Delgado, G. Sierra</AUTHOR>
	</AUTHORS>
	<YEAR>2008</YEAR>
	<TITLE>Critical Lines and Massive Phases in Quantum Spin Ladders with Dimerization</TITLE>
	<PLACE_PUBLISHED>Phys. Rev. B </PLACE_PUBLISHED>
	<PUBLISHER>Phys. Rev. B</PUBLISHER>
	<VOLUME>77</VOLUME>
	<PAGES>094415</PAGES>
	<URL>http://arxiv.org/abs/0707.4452</URL>
</RECORD>
</RECORDS></XML>