@article{Rockwood:1989:TDM,
  author = {Alyn P. Rockwood},
  title = {The Displacement Method for Implicit Blending Surfaces in Solid Models},
  journal = {ACM Transactions on Graphics},
  volume = {8},
  number = {4},
  pages = {279--297},
  month = oct,
  year = {1989},
}