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公开(公告)号:US2713339A
公开(公告)日:1955-07-19
申请号:US35928053
申请日:1953-06-03
Applicant: NAT RES DEV
Inventor: FREDERICK SAYERS CECIL
公开(公告)号:US2713339A
公开(公告)日:1955-07-19
申请号:US35928053
申请日:1953-06-03
Applicant: NAT RES DEV
Inventor: FREDERICK SAYERS CECIL