Construct an XPath query which filters nodes based on the quantity of its children?

I have the following XML:

<person-group person-group-type="author">
    <name>
        <surname>Chen</surname>
        <given-names>J-Y</given-names>
    </name>
</person-group>
<person-group person-group-type="author">
    <name>
        <surname>Cisse</surname>
        <given-names>F</given-names>
    </name>
</person-group>
<person-group person-group-type="author">
    <name>
        <surname>Dahou</surname>
        <given-names>T</given-names>
    </name>
    <name>
        <surname>Foucher</surname>
        <given-names>V</given-names>
    </name>
</person-group>

I am trying to design an XPath query which will only return elements only if they have more than one element.

I've tried everything within my knowledge, and also combed through XPath and XQuery documentation for the past few hours. Nothing I've read tells me if I can filter nodes based on the quantity of their children.

Thanks.