1. Cooper, L. A., & Shepard, R. N. Chronometric studies of the rotation of mental images. In W. G. Chase (Ed.),Visual information processing. New York: Academic Press, in press.
2. Shepard, R. N. Studies of the form, formation, and transformation of internal representations. In E. Galanter (Ed.),Cognitive mechanisms. Washington, D.C: Winston & Sons, in press.
3. Shepard, R. N., & Metzler, J. Mental rotation of three-dimensional objects. Science, 1971, 171, 701–703.