Php function only returning one post when i want to return all the post of a category

Hi have this function that is meant to return all the post of category news, the problem is that is only returning one post of that category I want to return all the post.

//function to display the third last news published
function wptuts_third_last_news_shortcode($atts, $content=null) {
query_posts( 'category_name=news' );   if (have_posts()) :
      while (have_posts()) : the_post();
	 		 $blog_link = get_permalink(); // this si the link
         $return_string =  "<a href=" .$blog_link .">" . get_the_title() . "</a>" ;
   return $return_string;
add_shortcode( 'third_last_news', 'wptuts_third_last_news_shortcode');