Beth Brown Reinsel (knittingtraditions.com) is the author of my go-to gansey design book, Knitting Ganseys. It has recently (Autumn 2018) been updated and republished, with new patterns, by Interweave Press.
If you have become interested in traditional knitting but somehow not hove stumbled upon her yourself yet, you should go to her webpage now. If you are looking for yarn to knit her lovely Winter Sanquhar glove pattern, she will have some in stock shortly (I have an order in the works for her as I type this).
For people interested in natural dyes, Kathy Hatori of Botanical Colors carries a wide range natural dyes and supplies. (I source most of my natural dyes from her).