@incollection{2011scherzerE,
  title =      "Fast Soft Shadows with Temporal Coherence",
  author =     "Daniel Scherzer and Michael Schw{\"a}rzler and Oliver
               Mattausch",
  year =       "2011",
  month =      feb,
  booktitle =  "GPU Pro 2",
  editor =     "Wolfgang Engel",
  isbn =       "978-1568817187",
  publisher =  "A.K. Peters",
  Pages =      "243–-255"
}