V. Havran, J. Bittner, H.-P. Seidl:
"Exploiting Temporal Coherence in Ray Casted Walkthroughs";
in: "Proceedings of Spring Conference on Computer Graphics", K. Joy (ed.); ACM, 2003, ISBN: 802231837x, 164 - 172.
http://aleph.ub.tuwien.ac.at/F?base=tuw01&func=find-c&ccl_term=AC04404546