His Divine Grace A.C. Bhaktivedanta Swami Prabhupada
Founder-Acarya of the International Society For Krishna Consciousness
In the Nectar of Devotion (Bhakti-rasamrta-sindhu) by Srila Rupa Gosvami, the chief disciple of Lord Sri Caitanya Mahaprabhu, the transcendental symptoms displayed by pure devotees are systematically described. One may consult The Nectar of Devotion for more detailed information on the science of devotional service.
Purchase The Nectar of Devotion - 1970 Edition