australian vs yorkie terrier

Question
How can i determine if my dog is yorkie or australian?   We bought him at a pet store - no papers - they said he was pure bred yorkie.  He weighs 10-11lb.  I have looked at Austrlian pictures and found a few pictures of short-haired larger yorkies- he could be either.  It doesn't matter to us which he is - just courious.  

Answer
Nancy,
The only way to tell is a DNA test, but it is very expensive.  The only other way is to buy from a reputable breeder, but if you are not showing the dog and just loving it, who cares.  If you are breeding it, that may be another story.  I would be suspect if there were no papers.
Nancy