@book{48465,
	author = {Rijksen, H. D. C.},
	title = {A fieldstudy on sumatran oraguntans (Pongo pygfmaeus Abelii Lesson 1827) ecology, behaviour and conservation},
	publisher = {Veenman & Zonen,},
	year = {1978},
	series = {Mededelingen Landbouwhogeschool},
	address = {Wageningen :}
}