New Directions in Fair Isle Knitting by Patty Knox, 1985, hardcover, oversize, 119 pages, out of print.
This is a decent book for Fair Isle reference. It is loaded with colour photos and patterns. Of course there is the how-to section with a few pages on designing your own knitwear. The pattern sizes range from young children to adults. The patterns are dated in style and colour but there is still much in the book to be useful. It is easily sourced at a small cost. If you come across the book at a reasonable price, I recommend purchasing it. However, I wouldn't go out of my way to obtain a copy.