Rāmānuja is the principal exponent of Viśiṣṭādvaita (qualified non-dual) Vedānta. He is traditionally dated 1017 to 1137 CE; some recent scholarship places him around 1077 to 1157. His commentary on the Brahma Sūtras is called the Śrī-bhāṣya, and it is the text this Atlas carries.
He reads the same sūtras as teaching a qualified non-duality: Brahman is the Supreme Person, free from all imperfection and possessing infinite auspicious qualities, and individual souls and the world are real, distinct, and inseparably dependent on Brahman, related to him as a body to its Self. The world is no illusion on this reading. Liberation comes through the grace of the highest Self, answered to sustained, devoted meditation and a life of disciplined duty; the liberated soul remains distinct, in communion rather than dissolution.