I have many books on bulbs but this one is unique. I love that the photos show single flowers side by side in the same photo with other flowers of the same family so that it is easy to compare them for size and color. For example one photo has blooms from 9 different Tazetta daffodils. There are other books that cover tulips well and some that cover daffodils, but this one includes the most complete list of hyacinths that I have ever seen--over 90 cultivars are described and most are photographed.
One alert is that the book was published by a British company and some of the varieties are not available in the US. Also, some of the varieties are heirlooms and are not widely available, anywhere.