Sri Ujjvala Nilamani: Rupa Gosvami is described as the bhaktirasacarya, or one who knows the essence of devotional service. His famous book Bhakti-rasamtra-sindhu is the science of devotional service, and by reading this book one can understand the meaning of devotional service. Another of his famous books is the Ujjvala-nilamani. In this book he elaborately explains the loving affairs and transcendental activities of Lord Krsna and Radharani.