1. Theories of group processes Barrett-Lennard, G. T. (1975/76). Process, effects and structure in intensive groups: A theoretical descriptive analysis. In C. L. Cooper (Ed.), (pp. 59-86). London: Wiley. (Published 1975; corrected paper-cover edition, 1976.)
2. Colloquium presentation to the Faculty of Social Work Barrett-Lennard, G. T. (1977). Prevention, healing and change on personal and system levels: An approach to integration. , Wilfred Laurier University, Ontario. (Edited as chap. 3 in Relationship at the centre – see below.)
3. A New Model of Communicational-Relational Systems in Intensive Groups;Barrett-Lennard G. T.;Human Relations,1979
4. Client-centered therapy and the person-centered approach: New directions in theory, research and practice Barrett-Lennard, G. T. (1984). The world of family relationships: A person-centered systems view. In R. F. Levant & J. M. Shlien (Eds), (pp. 222-242). New York: Praeger.
5. Client-centered and experiential psychotherapy in the nineties Barrett-Lennard, G. T. (1990). The therapy pathway reformulated. In G. Lietaer, J. Rombauts & R. Van Balen (Eds.), (pp. 123-153). Leuven, Belgium: Leuven University Press.