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|---|---|---|
 Date: 2014-10-08 02:46:52Rotary dial Chorded keyboard Adding machine Electronic engineering Technology Keying Push-button |
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| First Page | Document Content | |
|---|---|---|
Date: 2014-10-08 02:46:52Rotary dial Chorded keyboard Adding machine Electronic engineering Technology Keying Push-button |
Add to Reading List |
Human Factors Engineering Studies of the Design and Use of Pushbutton Telephone Sets By R . L. DEI NI GER (l\fanuscript received February 16, 1960)