This work was originally published before January 1, 1926 and the known author of this work:^[1]

• died before January 1, 1947,

OR

• died between January 1, 1947 and January 1, 1951, did not work during the Great Patriotic War (Eastern Front of World War II) and did not participate in it.

This work is in the public domain in the United States because it was published before January 1, 1926.

^[1] If the author of this work was subjected to repression and rehabilitated posthumously, countdown of copyright protection began not from the death date, but from the rehabilitation date. If the work was first published posthumously, the copyright term is counted from the date of that first publication, unless the author was later rehabilitated, in which case it runs again from that later rehabilitation date.