For those that sew and are into victoriana (and Edwardiana), I can recommend the following books:
Patterns of Fashion 2 - Janet Arnold (admittedly a little hard to come by, but a really good research if you want to sew historical reproduction garments). As this book goes up to the 1930s, it also covers some Belle Epoch, Jazz Age and other early diesel. Frankly, if you are into Jazz Age I would suggest you look at the youtube tutorials by The Closet Historian (you need a fair understanding of sewing for that one but it is very comprehensive) or Morgan Donner (you just need to know the basics for this one).
Authentic Victorian Fashion Patterns, a complete ladies' wardrobe - Kristina Harris (I have photographed several pages and patterns of this work, which you can download here: https://mega.nz/folder/l9YCgSrJ#9G6jWNySSidbgHIBdxM66g)
If you like more visuals, there is a bunch of costubers as they are called these days to have a look at: Bernadette Banner, Angela Clayton, Redthreaded, Dames a la Mode, Constance MacKenzie. I'm sure there's more, feel free to leave those in the comments!
For those that have the money to spare for a more extensive resource, there's also Foundations Revealed. I personally haven't ever subscribed to their service, as I've not had need for them, but I know people that have and they say they are worth every penny.
If you have other resources, please share them in the comments!