Does the "three-character sutra" belong to traditional culture or Buddhist sutra? Where can I buy the lecture CD of Amethyst? thank you

Saint Amethyst is a Confucian book suitable for children's enlightenment. Its content can be roughly divided into three parts: first, Confucian ethics and principles; The second is the historical overview of China from the legendary Yellow Emperor to the early years of Qing Dynasty; The third is the typical story of loyalty, filial piety and inspirational. The three-character classic is popular in language, elegant in phonology, catchy to read, and a good enlightenment book for teenagers.