This is the sixth volume in the spectacular, 16-volume super-encyclopedia "Handbook of the Birds of the World" (HBW for short). This volume covers Mousebirds, Trogons and the Coraciiformes, a diverse order including (among others) Rollers, Kingfishers, Bee-eaters and Hornbills.
Each family is introduced by a large chapter with the following sub-headings: Systematics, Morphological Aspects, Habitat, General Habits, Voice, Food and Feeding, Breeding, Movements, Relationship with Man, Status and Conservation. Species presentations follow. All species and many subspecies described in the text are illustrated on large, full-page color plates. There are also a lot of photos, all in color, in the introductory chapters.
The text is not sufficiently popularized, and the HBW is therefore primarily intended for large libraries or scientific institutions. The price is also forbidding. Each volume costs about 260 dollars, presumably excluding postage and packing. Take that times 16, and you have the approximate price for the entire series. It's 4,160 dollars. See my point?
However, if you have a very serious interest in, say, hornbills or bee-eaters, investing in this volume might nevertheless be a good idea. Apart from Amazon, all volumes are also available from Lynx Edicions through their website.