What is the correct xhtml for referring to an external style sheet?

<link class="url" target="_blank" rel="nofollow noreferrer" href="/to/?target=basic.css" type="text/css" rel="stylesheet" media="screen"/>

<link class="url" target="_blank" rel="nofollow noreferrer" href="/to/?target=print.css" type="text/css" rel="stylesheet" media="print"/>