1. Fletcher H: Articulation Testing Methods. Bel Tel Labs. Reprint 13-436, Nov 1929.
2. Meitzer PE: Instructional Courses on Functional Hearing Tests. Chicago, Am Acad OO, Oct 1946.
3. The Diaphragm Rod Prosthesis of the Middle Ear;Pohlman;Arch Otolaryngol,1943
4. Diseases of the Ear;Politzer,1926
5. Factors influencing the accuracy and interpretation of bone conduction hearing tests;Reger;JASA,1940