Here are some notes on sravama-dasa from NOI 8 from Gokulananda Das!

Regarding the references,

In Bhakti Sandarbha anuccheda 278 JG elaborates on the five stages of smaranam. In case you need them, I have the Bhakti Sandarbha translations by Satya Nārāyana Dāsa and H.H. Bhanu Svāmī in pdf format.

In your lecture, you mentioned that this topic shwos up in the works of Bhaktivinoda Thākura. I checked it up; there are elaborate explanations in Jaiva Dharma, chapter 40 and Harināma Cintamani, chapter 16.

FYI, Śivarama Svāmi wrote a synthesis on these stages in his Nava Vraja Mahima 8.36 (Introduction to Māha Mantra).

Ys,

Gokulānanda dāsa