@inbook {636,
	title = {A rich algal micro-flora from the Lower Permian of Jambi Province},
	booktitle = {The Pre-Tertiary Fossils of Sumatra and their Environments},
	series = {CCOP Technical papers},
	volume = {19},
	year = {1989},
	pages = {59-69},
	publisher = {United Nations},
	organization = {United Nations},
	address = {Bangkok},
	author = {Vachard, D.},
	editor = {Fontaine, H. and Gafoer, S.}
}
@article {629,
	title = {Geological map of the Bangko Quadrangle (0913-4), Sumatera, Scale 1 : 100,000. Detailed Geological Map, Indonesia},
	year = {1998},
	publisher = {Geological Research and Development Centre},
	address = {Bandung},
	author = {Suwarna, N. and Suharsono and Gafoer, S. and Amin, T.C. and Kusnama and Hermanto, B.}
}
