<ref xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:mml="http://www.w3.org/1998/Math/MathML" id="R6"><label>6</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Hudaib</surname><given-names>M</given-names></name><name><surname>Aburjai</surname><given-names>T</given-names></name></person-group><article-title>Volatile components of Thymus vulgaris L. from wild-growing and cultivated plants in Jordan</article-title><source>Flavour and Fragrance Journal</source><year>2007</year><volume>22</volume><issue>4</issue><fpage>322</fpage><lpage>327</lpage></element-citation></ref>