Free fermions and tau-functions
  We review the formalism of free fermions used for construction of tau-functions of classical integrable hierarchies and give a detailed derivation of group-like properties of the normally ordered exponents, transformations between different normal orderings, the bilinear relations, the generalized Wick theorem and the bosonization rules. We also consider various examples of tau-functions and give their fermionic realization. 
Alexander Alexandrov, Anton Zabrodin
math-ph hep-th math.MP nlin.SI