This work is in the public domain because it was published in the United States between 1929 and 1963, and although there may or may not have been a copyright notice, the copyright was not renewed. For further explanation, see Commons:Hirtle chart and the copyright renewal logs. 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.
Această lucrare este, de asemenea, în domeniul public în ţările şi zonele în care durata drepturilor de autoreste viaţa autorului plus 70 de ani sau mai puţin.
You must also include a United States public domain tag to indicate why this work is in the public domain in the United States. Câteva ţări au o durată a protecţiei dreptului de autor mai mare de 70 de ani: Mexic are 100 de ani, Jamaica are 95 de ani, Columbia are 80 de ani, iar Guatemala şi Samoa au 75 de ani. Acest fişier s-ar putea să nu fie în domeniul public în acele ţări, care pe deasupra nu ţin cont nici de regula celei mai scurte durate.