@Article{scholkopf98kpca,
   author =       {Bernhard {Sch\"olkopf} and Alex Smola and K.R. Muller},
   title =        {Nonlinear component analysis as a kernel eigenvalue 
problem},
   journal =      {Neural Computation},
   year =         {1998},
   volume =    {10},
   pages =     {1299--1319}
}

@article{brownetal93,
   author =      {Peter F. Brown and Stephen A. {Della Pietra} and 
                  Vincent J. {Della Pietra} and Robert~L. Mercer},
   title =       {The Mathematics of Statistical Machine Translation: 
                  Parameter Estimation},
   journal =     {Computational Linguistics},
   year =        1993,
   volume =      19,
   number =      2,
   pages =       {263-311}
}