| 361 / | HD | ELECTRICITY: ELECTRICAL SYSTEMS AND DEVICES |
| 139 | DF | CONTROL CIRCUITS FOR ELECTROMAGNETIC DEVICES {7} |
| 143 | DF | .~ Systems for magnetizing, demagnetizing, or controlling the magnetic field {5} |
| 149 | DF | .~.~ Demagnetizing {2} |
| 150 | ![]() | .~.~.~ Television degaussing |