References
- Davis H., et al. Harvard University Press. 1947, Hearing aids. An experimental study of design objectives. Cambridge, Mass.
- Ewertsen H. W. 1956; 520–525, Hearing Aid Evaluation. Archives of Otolaryngology, 64 (p.).
- Ewertsen H. W. 1962; 158–159, Minibox-audiometry. International Audiology, 1 (p.).
- Krarup B. S., Nielsen Scott. Lydtrykmaalinger i øregangen. Nordisk Audiologi 1965; 14: 90–94
- Røjskjær, Vognsen C. S. 1964; 5–15, Danish audiology and its institutions. International Audiology III (p.).