$re = '/class=\"four-column mosaicElement\">\R<a href=\"(.+?)\" title=\"(.+?)/m';
$str = '<li class="four-column mosaicElement">
<a href="https://example.com" title="Lorem ipsum">
...
</a>
</li>
<li class="four-column mosaicElement">
<a href="https://example.org" title="Lorem ipsum">
...
</a>
</li>';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php