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UN works not in the annex to Administrative Instruction ST/AI/189/Add.9/Rev.1 (available in English) published in the US before 1978 are in the public domain because they were published without a copyright notice. UN works not in the annex to ST/AI/189/Add.9/Rev.1 published in the US between 1978 and 17 September 1987 are in the public domain because they were published without a copyright notice and their copyright was not subsequently registered with the U.S. Copyright Office within 5 years (from 1978 through 1993 the UN did not register any document published in the US before 17 September 1987).

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