Swami Vivekananda & Edward T. Sturdy 
Narada Bhakti Sutras [EPUB ebook] 
The Path of Love for God

The Narada Bhakti Sutras are 84 aphorisms (short doctrines) on the love of God (bhakti) attributed to Narada, a sage from Hindu mythology, and considered a classic of bhakti literature.
Swami Vivekananda wrote a free translation of these sutras and gave a lecture on them to a small group of students on the 'Thousand Islands’ in the St. Lawrence River in New York State.
His disciple Edward Sturdy also translated the sutras with the help of Vivekananda and wrote a commentary on them that clearly bears his signature.
The Narada Bhakti Sutras describe the still current way to love God, which exists in all religions.