1. Shultz, T. R. Concepts of natural and logical necessity. Paper presented at the biennial meeting of the Society for Research in Child Development, April 1981.
2. Silverman, I. W. & Briga, J. Does conservation training provoke the child to discover new rules for judging quantity. Paper presented at the biennial meeting of the Society for Research in Child Development, April 1981.
3. Acredolo, C. & Acredolo, L. P. Equilibration and conservation. Paper presented at the meeting of the Piaget Society, May 1980.
4. Acredolo, C. The acquisition of conservation: A clarification of Piagetian terminology, some recent findings, and an alternative formulation. Human Development, 1981, 24, 120–137.
5. Acredolo, C. & Acredolo, L. P. Identity, compensation, and conservation. Child Development, 1979, 50, 524–535.