Fashion Sourcebook 1920's by Charlotte Fiell and Emmanuelle Dirix is an enormous brick of gold for fashion history enthusiasts, with pages upon pages of design sketches and photographs from the era, separated into categories of Daywear, Eveningwear, Outerwear, Accessories, and much more. It gives a clear look of both high fashion and everyday clothing in the Roaring 20's that's both educational and fun. There's also an informative forward with a comprehensive look at the elements of early 20th century life that shaped the world of fashion.
Another great feature of the book that I loved was the designer's index in the back, with a short biography of each designer, and a list of where their designs appear throughout the 576 page book. My favorite designer in the book is Atelier Bachroitz, whose feminine, whimsical, but still totally modern designs stood out among the sleek, straight lines of his contemporaries.