Geumgwang myeonggyeong (Sutra of Golden Light)

This Goryeo-dynasty book contains phonetic signs in vernacular Korean for reading sutras. Phonetic signs were added in the late 13th century, and 50 phonetic signs are used. The main topics of this sutra teach that anyone can realize the principles of Buddhism and become a Buddha and that a person can enjoy the pleasures of this life and govern the country well if that person persists in cultivating oneself in the Buddhist way through prayers while chanting mantras.