References – SN 22.29: Delight 
[Session] Readings by Ajahn Karuṇadhammo: [Aggregates]
Satipaṭṭhāna: The Direct Path to Realization by Venerable Anālayo, pp. 202-207.
Sutta: SN 22.5, Khandhasaṃyutta, “Concentration.”
Sutta: SN 22.29, Khandhasaṃyutta, “Delight.”
Sutta: SN 5.1, Bhikkhunīsaṃyutta, “Āḷavikā.”
Sutta: SN 5.9, Bhikkhunīsaṃyutta, “Selā.”