@article{Behrendt2005,
  author = {Stephan Behrendt and Carsten Colditz and Oliver Franzke and Johannes Kopf and Oliver Deussen},
  title = {Realistic Real-Time Rendering of Landscapes Using Billboard Clouds},
  journal = {Computer Graphics Forum (Proceedings of Eurographics)},
  volume = {24},
  number = {3},
  pages = {507--516},
  year = {2005},
}