1. Osborn, A.F.: Your Creative Power. Charles Scribner’s Sons, New York (1953)
2. Gordon, W.J.J.: Synectics, Harper & Brothers Publishers Inc. (1961)
3. Kawakita, J.: Idea Method, Chukoshinsho (1967). (in Japanese)
4. Nakayama, M.: Everything about the NM method-Theory and practical method of idea generation (1980). (in Japanese)
5. Ichikawa, K.: Science of Creaitivity. NHK Publishing, Inc. (1970)