I would recommend Sigrid Van Dort's book ,"the genetics of chicken colours- the basics". you can buy it from her in Europe .she has a website. that cost is about $82 USD. it is worth every penny. fabulous book. high-quality color. the first half of the book is a simple explanation of the genetics of chicken colors. the last half of the book is a treasure. it is an encyclopedia of pics of colored chickens, captioned by their genetic formulas. fantastic book .worth every penny. here's her website:
www.chickencolours.com
Best Regards,
Karen and the Light Sussex in Western Pennsylvania