如何排除加倍的DOMDocument元素

Question

I have trying to pull titles from a page. Everything seems to work so far but I've got doubled results. For example I'm getting h3 titles. On the page is one time but in the source is 2 times.

Here is the example

<span data-img-type='cvr' data-img-att-alt='Cover of Greek Mythology' data-img-size-xs='image.jpg'></span>
<h3> Cover of Greek Mythology </h3>

This will return

Cover of Greek Mythology
Cover of Greek Mythology

I'm targeting only h3 elements but they still appear doubled. How can I remove repeated elements?

Here is what I have so far

$html = file_get_contents('https://example.com/'); 

$scriptDocument = new DOMDocument();

libxml_use_internal_errors(TRUE); 

if(!empty($html)){ 

    $scriptDocument->loadHTML($html);
    libxml_clear_errors(); 
    $scriptDOMXPath = new DOMXPath($scriptDocument);
    //get all the h3's with an class
    $scriptRow = $scriptDOMXPath->query('//h3[@class]');
    //check
    if($scriptRow->length > 0){
        foreach($scriptRow as $row){
            echo $row->nodeValue . "<br/>";
        }
    }
}