@InProceedings{pontt_etal:1994,
      AUTHOR = {Pontt, J. and Pontt, C and Silva, L. and Rodriguez, J.},
      TITLE = {Perturbatory phenomena in mineral processing systems.},
      YEAR = {1994},
      BOOKTITLE = {Congreso internacional de tecnolog{\~A}­a de minerales,},
      ADDRESS = { S{\~A}£o Paulo, Brasil}
}