วันนี้หาเจอบทความอธิบาย บทความจาก nytimes.com ครับ
http://www.propertyintangible.com/2010/01/15-of-sherlock-holmes-under-copyright.html section 304 of the Copyright Act set the copyright term at 75 years from date of publication.
But, enter the Sonny Bono Copyright Term Extension Act, effective on October 27, 1998.
Rather than the 75 year extension previously provided originally under the 1976 Act,
the Sonny Bono Act changed the extension to 95 years.
Out of four novels and 56 short stories, nine short stories are still under copyright.
What that means about using the Sherlock Holmes character at all is another story.
และยังมี บทความหัวข้อว่า
NY Times Takes Up The Case Of Sherlock Holmes And The Lost Public Domain... But Gets It Wrong
http://techdirt.com/articles/20100119/2318397826.shtml