Populasi dan tingkahlaku bekantan (Nasalis larvatus) di Suaka Margasatwa Tanjung Puting, Kalimantan Tengah = Behaviour and population density of proboscis moneky (Nasalis larvatus) at Tanjung Puting Game Reserve, Central Kalimantan - Bismark, M. (Laporan (Lembaga Penelitian Hutan) ;, 1980)