Mathematical teaching block
USD338929S · kind S · design
1Cited by
7References
1Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 15, 1990 |
| Grant date | Aug 31, 1993 |
| Priority date | — |
| Expiry date | Aug 31, 2007 |
Classification
- Technology area (CPC —)General
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.