...public domain * in the United States because 1. it was first published outside the United States (and not published in the U.S. within 30 days) * and * 2. it was first published before 1978 without complying with U.S. copyright formalities or after 1978 without copyright notice * and * 3. it was in the public domain in its home country on the URAA date (). This work is also in the public domain in countries and areas where the copyright term is the author's * life plus 75 years or less * . ...
--Wikipedia Public Domain License, Version PD-old-75-1996. (Paragraph 1.)