@article{laine2005siggraph,
author = {Samuli Laine and Timo Aila and Ulf Assarsson and Jaakko Lehtinen and Tomas Akenine-M\&\#246;ller},
title = {Soft Shadow Volumes for Ray Tracing},
journal = {ACM Transactions on Graphics},
volume = {24},
number = {3},
year = {2005},
pages = {1156--1165},
publisher = {ACM Press},
}