This map is from "The Lhota Nagas", page 233. It is available for download at:
https://archive.org/details/cu31924024053534
Shown: Lhotas, Aos, Konyaks, Phoms, Changs, Sangtams, Yachungrr, Semas, Sangtams, Rengmas, Angamis, Naked Rengmas, Southern Sangtams, Tangkhuls