Barnes-Holmes, Yvonne and Barnes-Holmes, Dermot and Smeets, Paul M. and Strand, Paul and Friman, Patrick (2004) Establishing Relational Responding in Accordance with More-than and Less-than as Generalized Operant Behavior in Young Children. International Journal of Psychology and Psychological Therapy, 4 . pp. 531-558.

Barnes-Holmes, Yvonne and Barnes-Holmes, Dermot and Smeets, Paul M. (2004) Establishing Relational Responding in Accordance with Opposite as Generalized Operant Behavior in Young Children. International Journal of Psychology and Psychological Therapy, 4 . pp. 559-586.