You might ask the parenting evaluator if they suggest any good material to read.

There is this one, but I dont know if it is good...

Joint Custody with a Jerk: Raising a Child with an Uncooperative Ex, A Hands on, practical guide to coping with custody issues that arise with an uncooperative ex-spouse

I bought and read this good one, but it does not go into too much about working with a jerk...

http://www.amazon.com/Helping-Children-Divorce-Revised-Updated/dp/078795554X