1. Kraepelin, E.: Psychiatrie (seventh edition). Barth. Leipzig. 1904.
2. Kraepelin, E.: Dementia Praecox and Paraphrenias. Edinburgh. 1919.
3. Lewis, N. D. C., and Hubbard, L. D.: The mechanisms and prognostic aspects of the manic-depressive schizophrenic combinations. Am. Res. Nerv. and Ment. Dis., 11:539:608, 1931.
4. Hoch, P., and Rachlin, H. L.: An evaluation of manic-depressive psychosis in the light of follow-up studies. Am. J. Psychiat., 97:831–843, 1941.
5. Lewis, N. D. C., and Piotrowski, Z. A.: Clinical diagnosis of manic-depressive psychosis. In: Depression. P. Hoch and J. Zubin, editors. Grune & Stratton. New York. 1954.