(4) ——. Deaf-Mutes in the United States. Analysis of the census of 1910 with summary of state laws relating to the deaf as of January 1, 1918. Washington, 1918.
(5) ——. The Blind in the United States 1910. Washington, 1917.
(6) Niceforo, Alfredo. Les Classes pauvres. Recherches anthropologiques et sociales. Paris, 1905.
(7) Goddard, Henry H. Feeble-mindedness, Its Causes and Consequences. Chap. i, "Social Problems," pp. 1-20. New York, 1914.
(8) Popenoe, Paul B., and Johnson, Roswell H. Applied Eugenics. Chap. ix, "The Dysgenic Classes," pp. 176-83. New York, 1918.
(9) Pintner, Rudolph, and Toops, Herbert A. "Mental Test of Unemployed Men," Journal of Applied Psychology, I (1917), 325-41; II (1918), 15-25.
(10) Oliver, Thomas. Dangerous Trades. The historical, social, and legal aspects of industrial occupations affecting health, by a number of experts. New York, 1902.
(11) Jarrett, Mary C. "The Psychopathic Employee: a Problem of Industry," Bulletin of the Massachusetts Commission on Mental Diseases, I (1917-18), Nos. 3-4, 223-38. Boston, 1918.
(12) Thompson, W. Gilman. The Occupational Diseases. Their causation, treatment, and prevention. New York, 1914.
(13) Kober, George M., and Hanson, William C., editors. Diseases of Occupation and Vocational Hygiene. Philadelphia, 1916.