1. TIME IN GEOLOGICAL EXPLANATIONS AS PERCEIVED BY ELEMENTARY-SCHOOL STUDENTS
2. (1981). Children's concepts about time no barrier to understanding the geologic past. Unpublished doctoral dissertation, Cornell University, Ithaca.
3. Development and Analysis of a Spatial Visualization Test for Middle School Boys and Girls
4. The Effect of Instruction on Spatial Visualization Skills of Middle School Boys and Girls
5. & (1982). The development of causal reasoning. In (Ed.), The developmental psychology of time (pp. 209-255). New York: Academic Press.