I hadn't heard of him, and google brought me right to his website:

Pete Walker, M.A. Psychotherapy

Judith Herman's book on trauma and recovery is also great.

I thought the information about co-dependency (usually a term I balk at) was really well-explained.

What hit me hardest is what he said about grieving a childhood (and for me, a big part of adulthood) where you didn't look out for yourself properly or establish healthy boundaries. That just feels like a big loss today. I have never heard anyone describe this as self abandonment.