The Duke Chronicle editors did not include a copyright notice at all, so this issue is generally public domain. The Volkswagen ad on this page includes a copyright notice; however, the notice doesn't include the year of first publication and is therefore defective.
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (50 p.m.a.), Mainland China (50 p.m.a., not Hong Kong or Macao), Germany (70 p.m.a.), Mexico (100 p.m.a.), Switzerland (70 p.m.a.), and other countries with individual treaties.
This work is in the public domain because it was published in the United States between 1929 and 1977, inclusive, with a defective copyright notice (copyright notice information) containing at least one of the following defects:
Notice is dated more than one year later than the actual date of first publication;
Notice does not include a named claimant or does not name the actual copyright holder;
Notice is illegible or concealed from view;
It is a printed literary, musical, or dramatic work that does not include the year.
A defective notice does not invalidate copyright in cases where the error is immaterial and would not mislead an infringer, such as an abbreviated name. Additionally, foreign works created outside the US are subject to copyright restoration even with a defective notice. It is not in the public domain in the countries or areas that do not apply the rule of the shorter term for US works, such as Canada, mainland China (not Hong Kong or Macao), Germany, Mexico, Switzerland, and other countries with individual treaties.