共 54 条
[1]
[Anonymous], 1999, CRADL INV BRIT PAT 1
[2]
[Anonymous], 2001, NBER PATENT CITATION
[3]
[Anonymous], 1875, SCI AM, V33
[4]
[Anonymous], NY TIMES
[5]
[Anonymous], 1851, SCI AM, V7
[6]
[Anonymous], 2001, INNOVATION POLICY EC
[7]
[Anonymous], 1876, PRACTICAL MAGAZINE, V6
[8]
[Anonymous], 1875, NY TIMES
[9]
[Anonymous], 2000, PROTECTING THEIR INT
[10]
[Anonymous], 1856, SCI AM, V12