Ruggiero, V. R. (2001). The art of thinking: A guide to critical and creative thought (6th ed.). Longman.
Lua i Stíl Chicago (17ú heag.)Ruggiero, Vincent R. The Art of Thinking: A Guide to Critical and Creative Thought. 6th ed. New York: Longman, 2001.
Lua MLA (9ú heag.)Ruggiero, Vincent R. The Art of Thinking: A Guide to Critical and Creative Thought. 6th ed. Longman, 2001.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.