The Upaniṣads — the philosophical core of the Vedic tradition, revealing the nature of Brahman, the Ātman, knowledge, action and liberation. The ten principal Upaniṣads together with select minor Vaiṣṇava Upaniṣads.
A dictionary in questions: what is bondage and what is freedom, what is ignorance, who is a knower, what the great sayings mean. Twenty-nine short answers — a convenient handbook of Vedānta's whole vocabulary.