Like with books like Fashion Sourcebook 1920s, Fashion Sourcebook 1930s, and 1940s Fashion: The Definitive Sourcebook, it boasts a fabulous title which promises all sorts of very lovely things that's give you all sorts of glee... But which it absolutely doesn't actually contain an ounce of in any tangible or useful way.
It's pretty much just 90% pictures, and 10% vaguely useful information; not particularly interesting short of various visual oo's and ahh's, and lacking any real substance.
I guess the book is useful if all you really want to do in the first place is look at fashion plates for visual reference all day. But it's useless if what you're looking for is to learn anything legitimate about the fashion of the era outside of more than what it merely looked like. And if that's the case, you're sorely out of luck in this case.
Better luck finding what you're looking for elsewhere, because you sure won't be finding it here.