Ruggiero, V. R. (2001). The art of thinking: A guide to critical and creative thought (6th ed.). Longman.
Chicago-referens (17:e uppl.)Ruggiero, Vincent R. The Art of Thinking: A Guide to Critical and Creative Thought. 6th ed. New York: Longman, 2001.
MLA-referens (9:e uppl.)Ruggiero, Vincent R. The Art of Thinking: A Guide to Critical and Creative Thought. 6th ed. Longman, 2001.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.