A. G. Voloboi V. A. Galaktionov Kirill Dmitriev Edward A. Kopylov Bidirectional Ray Tracing for the Integration of Illumination by the Quasi-Monte Carlo Method. 258-265 2004 30 Programming and Computer Software 5 http://dx.doi.org/10.1023/B:PACS.0000043051.47471.aa db/journals/pcs/pcs30.html#VoloboiGDK04