In: Needs and Prospects of Child and Adolescent Psychiatry 1989; 171-178
A.R. Nicol, I. Kolvin, A. MacMillan, F. Wolstenholme, "Possible mechanisms of long-term effectiveness", pp. 171-178, in M.H. Schmidt and H. Remschmidt (eds.), "Needs and Prospects of Child and Adolescent Psychiatry", (Hogrefe and Huber, 1989).
Levitt must take credit for drawing attention to the need for systematic evaluation of child therapies. His reviews in the 1950s and most recently in 1971 threw down a challenge to us to demonstrate that child psychotherapies were effective.