Gruber, H. E., & Terrell, G. (1962). Contemporary approaches to creative thinking: A symposium held at the university of Colorado. Atherton.

Gruber, Howard E., and Glenn Terrell. Contemporary Approaches to Creative Thinking: A Symposium Held at the University of Colorado. London: Atherton, 1962.

Gruber, Howard E., and Glenn Terrell. Contemporary Approaches to Creative Thinking: A Symposium Held at the University of Colorado. Atherton, 1962.