@article{ Sumner:1999:ASM,
  author = "Robert Sumner and James F. O'Brien and Jessica K. Hodgins",
  title = "Animating Sand, Mud, and Snow",
  year = "1999",
  month = mar,
  journal = "Computer Graphics Forum",
  volume = "18",
  number = "1",
  pages = "17--26",
}