There are many, many threads about the Biewers on YT. You can do a search for them and read up... Briefly -- the Biewer is not a mixed breed... it originated with two traditional yorkies that both carried a recessive piebald gene. It was developed in Germany -- and has been bred to a standard. A tri-color head... Blue/Gold and White. All four legs, chest and tummy are white, along with the tip of the tail. (The tails are not docked) On the body, the hair is a combination of blue/white. There are several breed clubs here in the US that you can check into. Also, you can google Biewer Yorkshire Terrier and you will find a wealth of information. The most important thing I can tell you is do your own research... Just because someone says they are a "breeder" doesn't mean they are an expert! If you want to check out a great breeder -- try
www.magnoliasmagnificentyorkies.com Also you can try biewertalk.com and the bytnc.com
Here's a pic of my baby that I got from snow yorkies who's a member here.