Singer, M. T. (1995). Cults: Implications for family therapists. In R. H. Mikesell, D.-D. Lusterman, & S. H. McDaniel (Eds.), Integrating family therapy: Handbook of family psychology and systems theory (pp. 519-527). Washington, DC, US: American Psychological Association.
http://dx.doi.org/10.1037/10172-029
present in some detail the initial phase of consultation / introduce some basic parameters of working during later phases, particularly after the family member has left the cult (PsycINFO Database Record (c) 2016 APA, all rights reserved)