Ruggiero, V. R. (1991). The art of thinking: A guide to critical and creative thought (3rd.ed.). Harper Collins.

Ruggiero, Vincent Ryan. The Art of Thinking: A Guide to Critical and Creative Thought. 3rd.ed. New York: Harper Collins, 1991.

Ruggiero, Vincent Ryan. The Art of Thinking: A Guide to Critical and Creative Thought. 3rd.ed. Harper Collins, 1991.