English: The printing equipment company ATF explicitly states in its 1923 manual that its goal is to 'discourage unhealthy competition' in the printing industry.
Copyrighted 1923-12-15, registered as A765665. A search of the relevant issues of the Catalog of Copyright Entries shows no renewal, so copyright expired in 1951.
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 (70 years p.m.a.), Mainland China (50 years p.m.a., not Hong Kong or Macao), Germany (70 years p.m.a.), Mexico (100 years p.m.a.), Switzerland (70 years p.m.a.), and other countries with individual treaties.