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发明名称
Telephone system
摘要
申请公布号
US2020458(A)
申请公布日期
1935.11.12
申请号
US19340729782
申请日期
1934.06.09
申请人
BELL TELEPHONE LABORATORIES, INCORPORATED
发明人
DAHL JACK F.
分类号
H04Q3/00
主分类号
H04Q3/00
代理机构
代理人
主权项
地址
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