1. Maeda Y, Hayashi H, Suzuki T (1989) Clinical study of operative mental dysfunction in aged patients (in Japanese). Ronen Syokakibyo (Geriatr Gastroenterol) 2:75?81
2. Morichika H, Hayashi H, Suzuki T (1990) Post-operative mental dysfunction in aged patients ? Studied by the Yamaguchi University scale ? (in Japanese). Ronen Syokakibyo (Geriatr Gastroenterol) 3:63?68
3. Komazawa T (1983) Scaling theory and analysis of data (in Japanese). Asakura Syoten, Tokyo, pp 45?88
4. Hayashi H, Murakami T, Honma K, Tangoku A, Johno N, Maeda Y, Morichika H, Suzuki T (1989) Results of surgical treatment for esophageal cancer in aged patients (in Japanese). Ronen Syokakibyo (Geriatr Gastroenterol) 2:179?184
5. Knox SJ (1961) Severe psychiatric disturbances in the post-operative period. J Ment Sci 107:1078?1096