An approach to the classification of p-brane solitons
  We give a review of some recent work on the construction and classification of $p$-brane solutions in maximal supergravity theories in all dimensions $4\le D\le 11$. These solutions include isotropic elementary and solitonic $p$-branes, dyonic $p$-branes, and multi-scalar $p$-branes. These latter two categories include massless strings and black holes as special cases. For all the solutions, we analyse their residual unbroken supersymmetry by means of an explicit construction of the eigenvalues of the \bog matrix, defined as the anticommutator of the conserved supercharges. 
H. Lu and C.N. Pope