You can find breeders in the Akc reffereal near your area or a Dog Show. Then if you have luck finding a breeder they can show you a mating paper before the pups are born.
http://i45.photobucket.com/albums/f9...efpedigree.png
Then if you want you can search
- World Pedigree DataBase Yorkshire Terrier, Yorkshire terrier Pedigree DataBase.
And see if theres any infor there. Or just search the web the show name. But a breeder usuallly will sell you pet quality and a good breeder won't gouge you. And you most likely will get a good health guarrentte. But it's up to the buy to do all the esearch. Not all ppl are honest. JME