@inproceedings{FP09,
  Author = {K.~Figueroa and R.~Paredes},
  Booktitle = {Proceedings of the 2nd International Workshop on Similarity Search and Applications (SISAP 2009)}, 
  Note = {doi: http://doi.ieeecomputersociety.org/10.1109/SISAP.2009.33},
  Pages = {91--98},
  Publisher = {IEEE Computer Society Press}, 
  Title = {Approximate direct and reverse nearest neighbor queries, and the $k$-nearest neighbor graph}, 
  Year = {2009}}