Uniqueness of Fisher plots and their inferred (nuclear) liquid-vapor   phase diagrams
  A detailed study of the lattice gas (Ising) model shows that the correct definition of cluster concentration in the vapor at coexistence with the liquid leads to Fisher plots that are unique, independent of fixed particle number density $\rho_{\text{fixed}}$, and completely reliable for the characterization of the liquid-vapor phase diagram of any van der Waals systems including nuclear matter. 
J. B. Elliott, L. G. Moretto and L. Phair