Try asking this lady at the YORKSHIRE TERRIER CLUB. Sec. Mrs Mitchell. Tel: 01235 833171...or..try looking on Pet Plans website
http://www.petplan.co.uk/community/findapet.asp ...or......Or go to the Kennel Club website who also have a breeders list search facility...see link
http://www.the-kennel-club.org.uk/asp/PSAR/ 