Four sampradaya acaryas
Sri Caitanya-caritamrta
CC Antya-lila
A Vaiṣṇava should study the commentaries on the Vedānta-sūtra written by the four sampradāya-ācāryas.
CC Antya 2.95, Purport: A Vaiṣṇava should study the commentaries on the Vedānta-sūtra written by the four sampradāya-ācāryas, namely Śrī Rāmānujācārya, Madhvācārya, Viṣṇu Svāmī and Nimbārka, for these commentaries are based upon the philosophy that the Lord is the master and that all living entities are His eternal servants. One interested in studying Vedānta philosophy properly must study these commentaries, especially if he is a Vaiṣṇava. These commentaries are always adored by Vaiṣṇavas. The commentary by Śrīla Bhaktisiddhānta Sarasvatī is elaborately given in the Ādi-līlā, Chapter Seven, text 101.