@article{Callahan:2008:DVR,
	author={S. Callahan and J. Callahan and C. Scheidegger and C. Silva},
	journal={IEEE/AIP Computing in Science and Engineering},
	number=1,
	pages={88--92},
	title={Direct Volume Rendering: A 3D Plotting Technique for Scientific Data},
	volume=10,
	year=2008,
}