There is a breeder review section here that you can peruse:
www.rigair.com Ilona Rodionova
Betty Anne Durrer and Vicki Lyn
Loretta Serafina Oz Yorkshire Terriers
All the above are members of the Canadian Yorkshire Terrier Club.
www.cyta.ca All the above breeders are in Southern Ontario
I have known the above for well over 6yrs and believe them to be very responsible breeders.