| 204 / | HD | CHEMISTRY: ELECTRICAL AND WAVE ENERGY |
| * | DD | PROCESSES AND PRODUCTS {7} |
| 157.15 | DF | .~ Processes of treating materials by wave energy {6} |
| 157.4 | DF | .~.~ Process of preparing desired inorganic material {11} |
| 157.52 | ![]() | .~.~.~ Hydrogen containing product produced |