(This is an entry in the Annotated Bibliography.)
Langley, Susan. Vintage Hats & Bonnets; 1770 – 1970; Identification and Values. 2nd ed. Paducah, Kentucky: Collector Books, 2009.
This book is better regarded, with generally more positive reviews, than most books on historical and vintage hats and other headwear. It is intended for use by collectors of vintage headwear. I have not read the full text, but in spite of limited direct citations and references, it seems generally well-researched. Images are plentiful, in full color where applicable, with a helpful mixture of period portraits and photographs, period fashion plates, and photographs of extant hats and bonnets. The organization of the book is chronological, beginning in the late 18th century. Mysteriously, 19th century fabric caps for indoor wear are consistently referred to as bonnets, possibly because this term was in use for such garments in French. The twentieth century takes up a large proportion of the book’s space, going as far as 1970. It is not instructional. It has full color images. It contains a bibliography.