1. Kraepelin, E.: Psychiatrie, sixth edition. Johann Ambrosius Barth, Leipzig, 1899.
2. Meyer, Adolf: What do histories of cases of insanity teach us concerning preventive mental hygiene during the years of school life? Psychological Clinic, XI:89, 1908.
3. Webster's Universal Dictionary of the English Language. The World Syndicate Publishing Company, New York, 1936.
4. Hutchings, Richard H.: A Psychiatric Word Book, fifth edition. The State Hospitals Press, Utica, 1937.
5. Rosanoff, Aaron J.: Manual of Psychiatry, sixth edition. John Wiley and Sons, New York, 1927.