Exact form factors in integrable quantum field theories: the scaling   Z(N)-Ising model
  A general form factor formula for the scaling Z(N)-Ising model is constructed. Exact expressions for matrix elements are obtained for several local operators. In addition, the commutation rules for order, disorder parameters and para-Fermi fields are derived. Because of the unusual statistics of the fields, the quantum field theory seems to be not related to any classical Lagrangian or field equation. 
H. Babujian, A. Foerster, and M. Karowski