Labrador Retreiver

The New Complete Labrador Retriever by Helen Warwick

Training Your Labrador Retriever by September B. Morn(Barron's)

Labrador Retrievers, Volume 1 From the Editors of Dog Fancy Magazine

Chihuahua

The Chuhuahua, An Owner's Guide to a Happy Healthy Pet by E. Ruth Terry

The Essential Chihuahua, Howell Book House

Pugs

The Complete Pug by Ellen S. Brown

Pugs by Barron's