A symmetry reduction technique for higher order Painlev\'e systems
  The symmetry reduction of higher order Painlev\'e systems is formulated in terms of Dirac procedure.   A set of canonical variables that admit Dirac reduction procedure is proposed for Hamiltonian structures governing the ${A^{(1)}_{2M}}$ and ${A^{(1)}_{2M-1}}$ Painlev\'e systems for $M=2,3,...$. 
H. Aratyn, J. F. Gomes and A. H. Zimerman
nlin.SI