Hardly a month ago I consulted him on the lexical element paN as I was not satisfied with the statements about it in some handbooks; he referred me to his Non-Aryan linguistic elements in the Atharvaveda which he had gifted me around 10 years ago and which I should have consulted in the first place: the answer was already there.
The full reference is:
Non-Aryan linguistic elements in the Atharvaveda : a study of some words of Austric origin / by Dr. Abhijit Ghosh
Calcutta : Sanskrit Pustak Bhandar, 2000.
Another well-known contribution by him is the edited volume:
Ātharvaṇā : a collection of essays on the Atharva Veda with special reference to its Paippalāda tradition / ed. by Abhijit Ghosh.
Kolkata : Sanskrit Book Depot, 2002.