Nice! I presume you mean
Ashtanga Yoga as given in the
Patanjali Yoga Sutras. Edwin Bryant's translation based on traditional commentaries is a must read. One interesting old classic on psychological application is Geraldine Coster's
Yoga And Western Psychology : A Comparison -
https://archive.org/details/in.ernet.dli.2015.238168/page/n3...You might also find this previous comment of mine useful - https://news.ycombinator.com/item?id=41538322
