Hearing aids /
| Main Author: | |
|---|---|
| Format: | Government Document Book |
| Language: | English |
| Published: |
Washington :
U. S. Govt. Print. Off.,
1953
Washington : U.S. Govt. Print. Off, 1953 Washington, U.S. Govt. Print. Off., 1953 |
| Series: | Circular of the Bureau of Standards ;
no. 534 Circular of the National Bureau of Standards ; 534 National Bureau of Standards circular ; 534 |
| Subjects: |