REFERENCES
- Survey of the occupational environment; an essential of industrial medical practice. J.A.M.A. 162: 1387 (December 8) 1956.
- Fleming, A. J., D'alonzo, C. A. and Zapp, J. A.: Modern Occupational Medicine. Philadelphia, Lea & Febiger, 1954.
- McGee, L. C.: Manual of Industrial Medicine. Ed. 3. Philadelphia, University of Pennsylvania Press, 1956.