M. Vidal, A. da Silva, E. de Moura, and J. Cavalcanti. Proceedings of the 29th annual international ACM SIGIR conference on Research and development in information retrieval, page 292--299. New York, NY, USA, ACM, (2006)
A. Neto, R. Fortes, and A. da Silva Filho. Proceedings of the 26th annual ACM international conference on Design of communication, page 277--278. New York, NY, USA, ACM, (2008)
H. Silva, V. Bonato, C. Silva, and R. Santos. Abstract Book of the XXIII IUPAP International Conference on Statistical Physics, Genova, Italy, (9-13 July 2007)