Spin in the path integral: anti-commuting versus commuting variables
  We discuss the equivalence between the path integral representations of spin dynamics for anti-commuting (Grassmann) and commuting variables and establish a bosonization dictionary for both generators of spin and single fermion operators. The content of this construction in terms of the representations of the spin algebra is discussed in the path integral setting. Finally it is shown how a `free field realization' (Dyson mapping) can be constructed in the path integral. 
F.G. Scholtz, A.N. Theron and H.B. Geyer (ITP, University of   Stellenbosch, Stellenbosch, South Africa)