@inproceedings{she-mac-tak-05-effp,
  author = {Li Shen and Takashi Machida and Haruo Takemura},
  title = {Efficient Photometric Stereo for Three-Dimensional Surfaces with Unknown {BRDF}},
  booktitle = {Proceedings of the 5th International Conference on 3-D Digital Imaging and Modeling (3DIM'05)},
  pages = {326--333},
  year = 2005
}