The author died in 1968, so this work is in the public domain in its country of origin and other countries and areas where the copyright term is the author's life plus 50 years or fewer.

The author died in 1954, so this work is in the public domain in its country of origin and other countries and areas where the copyright term is the author's life plus 60 years or fewer.

1. This is a photographic work, audiovisual recording, motion picture, sound recording, or broadcast work, and at least 50 years have elapsed since its first publication or it was not published within 50 years of authorship.
2. This is a work of applied arts, and at least 25 years have elapsed its first publication or it was not published within 25 years of authorship.
3. This is a work by a pseudonymous or anonymous author, and at least 50 years have elapsed since its first publication or it was not published within 50 years of authorship.
4. This is a work other than described above, and
   1. Its last author died at least 50 years ago, or
   2. Its last author died before publication and at least 50 years have elapsed since its first publication, or
   3. The author is a legal entity, and at least 50 years have elapsed since the first publication of the work or the work was not published within 50 years of authorship.
5. This work was created or commissioned by the Thai Government, and at least 50 years have elapsed since its first publication or it was not published within 50 years of authorship.