Patent:US5423682
Patent: | US 5423682 |
Title: | Numbering system teaching aid |
Date: | 13.06.1995 |
Place: | |
Country: | USA |
Person: | Hildebrandt, Raymond E. (7213 Huntcliff, West Bloomfield, |
Company: | |
Internal Links: | Lehrmittel |
Keywords: | |
Link to the patent office: (without guarantee) | ![]() ![]() |