No reputable breeder would sell their puppies through a pet store, and papers dont make a quality bred dog. Puppy mill dogs are often registered through the AKC (American Kennel Club) and CKC (Canadian Kennel Club) , as well as the other smaller kennel clubs like the Continental Kennel Club, and United Kennel Club. Registration Papers mean nothing except they come from registered parents, who come from registered parents and so on and so forth.... it has nothing to do with health, quality and conditions the dogs are kept/born in... no thanks.
NEVER buy a puppy from a pet store, they are 99% likely to be a puppy mill dog, it doesn't matter how cute they are... DO NOT SUPPORT PUPPY MILLS!!!