Koi and Garden Pools: A Complete Introduction
by Herbert R. Axelrod
Paperback: 125 pages
TFH Publications; ISBN: 0866223991; (June 1989)

The Interpet Encyclopedia of Koi: A Comprehensive Introduction to Keeping and Displaying These Magnificent Ornamental Fish, from Choosing Healthy Sto 
by Interpet Publishing (Hardcover)

Koi: Living Jewels of the Orient 
by Steve Hickling (Author) (Hardcover)

Koi: Everything About Selection, Care, Nutrition, Diseases, Breeding, Pond Design and Maintenance, and Popular Aquatic Plants (Barron's Complete Pet Owner's Manuals) 
by George C. Blasiola (Paperback)

The Tetra Encyclopedia of Koi 
by Tetra Press Staff, Tetra Press (Hardcover)
Out of Print - Try Used Books

How to Keep Koi: An Essential Guide 
by David Twigg (Author) (Hardcover)

The Ultimate Koi 
by Nick Fletcher (Editor) (Hardcover)
Out of Print - Try Used Books

The Professional's Book of Koi 
by Anmarie Barrie (Hardcover - September 1992)

Koi Appreciation: The First Step 
by Kate McGill (Hardcover)