Presgrave, Edward (1823): Tour in Sumatra. Account of a Journey from Mannar to Pasummah
Lebar, and the Ascent of Gunung Dempo, in the interior of Sumatra; performed by Order of the Hon.
Sir T. S. Raffles, Lieutenant-Governor of Fort Marlborough, in the year 1817. In: The Asiatic
journal and monthly register, Series 1, Vol. 15, S. 230–239, 321–330, 449–457
