i don't know that he wrote a book specifically on the ninth rasa, but it may still be worth looking at: V. Raghavan. The Number of Rasas. Madras: The Adyar Library, 1967.

On Fri, Oct 12, 2012 at 10:50 PM, Dipak Bhattacharya <dbhattacharya200498@yahoo.com> wrote:
Dear Colleague,
Many years ago I happened to read a book by Dr.V.Raghavan on the ninth rasa. I do not remember the exact title but could try to find that out from the Visva Bharati library. The difficulty is the the Central Library of the University is rearranging its books when a they have to work with a chronic shortage of staff. Still I shall try with my colleagues.
You can also try with Rūpa Gosvāmin of the Chaitanya movement. Chinmayee Chatterji had some works on Gosvāmin. But I myself have not read Chatterjee

Best
DB