The garments themselves may be termed "vintage", but their design is based on aesthetic elements that, to my mind, are classics and therefore, timeless.
Sewing
Resources for Pattern Drafting, Sewing, and Embellishments
I always find something to be gleaned from the combined experience of the curators, seamstresses, needleworkers and stylists who came before me, and this list of books and other resources are a good example.
Sewing Vintage & Illustrated Stories 