The Sandilya and Narada bhakthi sutras like the Bhagavata are fundamental works of mysticism . Sandilya bhakthi sutras seem to be older on account of its archaic tone and is evidently modeled on the pattern of the great philosophical Sutras. Narada Bhakthi sutra quotes sandilya but the sandilya does not quote Narada.
The Narada or Naradiya Purana is where Narada has described the duties which were observed in Vrihat Kalpa , that is called Naradiya, having twenty five thousand stanzas....It is communicated by Narada to the rishis in Naimisharanya, on the Gomati River.
Vamana Purana is that in which the four faced Brahma taught the three objects of existence , as subservient to the account of the greatness of Trivikrama, which treats also of the Shiva Kalpa , and which consists of ten thousand stanzas. It contains an account of the dwarf incarnation of Vishnu ; but it is related by Pulastya to Narada , and extends to but about seven thousand stanzas. Its contents can scarcely establish its claim to the character of a Purana.
Both the Sandilya and the Narada quote the Bhagavad Gita on the one hand, and later Bhakthi literature on the other.