Kalika Puran Chapter 13 [best] -

: The text is an essential source for the historical geography of early Assam , specifically describing the boundaries of Kamarupa and the sacred Brahmaputra River.

Some translations of the Kalika Purana vary in chapter numbering. In the "Vanathi" or "Kashi" editions, the slaying of Shumbha/Nishumbha might shift slightly (e.g., into Chapter 14 or 15). kalika puran chapter 13