Adityahrdayam - the Hymn to the sun god is ascribed to the sage Agastya, and occurs in Valmiki's Ramayana.  Agastya sang this hymn to lord Rama to establish the truth of the Vedantic dictum: the individual soul is identical with the universal Self.

The booklet provides Devanagari text (but no transliteration), followed by English translation of each verse.  Translation by S. Venkatasubramanyam.