The original Chinese text of the book “道德经” authored by 老子 is/are in the public domain and not protected by copyright because at least 100 years (viz. 2326) have passed since the author’s death in 300 BC.

The Czech translation of the book “道德经” (“Tao Te ťing”) authored by Rudolf Dvořák is/are in the public domain and not protected by copyright because at least 100 years (viz. 106) have passed since the author’s death in 1920.

The Japanese translation of the book “道德经” (“老子道徳経”) authored by 井上秀天 is/are in the public domain and not protected by copyright in a number of countries because at least 70 years (viz. 81) have passed since the author’s death in 1945.