Trace identities for skew-symmetric matrices
  We derive an expression for the product of the Pfaffians of two skew-symmetric matrices A and B as a sum of products of the traces of powers of AB and an expression for the inverse matrix A$^{-1}$, or equivalently B$^{-1}$, as a finite-order polynomial of AB with coefficients depending on the traces of powers of AB. 
M. I. Krivoruchenko
math-ph math.MP