The Tetra Encyclopedia of Koi
Professionals Book of Koi
Koi: A Complete Guide to their Care and Color Varieties
Koi Varieties
Koi (Complete Pet Owner's Manual)
Koi: Everything about Selection, Care, Nutrition, Diseases, Breeding, Pond Design and Maintenance, and Po (Barron's Complete Pet Owner's Manuals)
Koi: Living Jewels of the Orient
The World of Koi (Mini Encyclopedia Series for Aquarium Hobbyists)
Cult of the Koi