Mixed content?

From searching the archives and checking the XML spec, I think I already 
know the answer to this question.  But as a relative XML newbie, I thought 
I'd ask the list just to be sure.

Is there a way within a DTD to specify something like the following:

      <!ELEMENT QuizPage (#PCDATA | Question+)*>

That is, a QuizPage is made up of any combination of text and Question 
elements, BUT IT MUST HAVE AT LEAST ONE Question.

All I can seem to do is the following, which doesn't enforce my Question 
restriction:

      <!ELEMENT QuizPage (#PCDATA | Question+)*>

Jay