Nāṉ Ār?
"Who am I?" — Ramaṇa's answers to Sivaprakāśam Piḷḷai's questions, later rewritten by him as one essay of twenty paragraphs: not the body, senses or mind; the thought "I" is the root of every thought; ask where it rises.
Bhagavān's answers to Sivaprakāśam Piḷḷai, which he later rewrote himself as one continuous essay of twenty-one paragraphs.