FLASH MATH
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United States Patent and Trademark Office
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9
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1989-01-24
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1995-07-31
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historic |
details
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SPEECH UTILITY
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United States Patent and Trademark Office
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9
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1988-11-01
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1995-05-08
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historic |
details
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SPELL AND TELL
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United States Patent and Trademark Office
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9
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1988-09-13
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1995-03-20
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historic |
details
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TELL AND SPELL
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United States Patent and Trademark Office
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9
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1988-08-09
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1995-02-13
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historic |
details
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SONCOM
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United States Patent and Trademark Office
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9
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1987-10-13
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1994-04-18
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historic |
details
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FIRST MATH
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United States Patent and Trademark Office
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9
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1987-09-29
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1994-04-04
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historic |
details
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LELPS
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United States Patent and Trademark Office
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9
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1987-09-01
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1994-03-07
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historic |
details
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HIDE AND FIND
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United States Patent and Trademark Office
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9
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1987-09-01
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1994-03-07
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historic |
details
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