Issued Patents 1989
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4810197 | Three-dimensional instructional device for teaching physical properties and relationships between basic elements | — | 1989-03-07 |
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4810197 | Three-dimensional instructional device for teaching physical properties and relationships between basic elements | — | 1989-03-07 |