@article{DBLP:journals/pami/SanderZ92,
  author    = {Peter T. Sander and
               Steven W. Zucker},
  title     = {Singularities of Principal Direction Fields from 3-D Images},
  journal   = {IEEE Trans. Pattern Anal. Mach. Intell.},
  volume    = {14},
  number    = {3},
  year      = {1992},
  pages     = {309-317},
  ee        = {http://doi.ieeecomputersociety.org/10.1109/34.120326},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}