@article{knoll:09:cohoctiso,
  title={{Coherent Multiresolution Isosurface Ray Tracing}},
  author={Knoll, A.M. and Wald, I. and Hansen, C.D.},
  journal={The Visual Computer},
  volume={25},
  number={3},
  pages={209--225},
  year={2009},
  publisher={Springer}
}