Phenomenological renormalizaiton group approach to the anisotropic   two-layer Ising model
  The anisotropic two-layer Ising model is studied by the phenomenological renormalizaiton group method. It is found that the anisotropic two-layer Ising model with symmetric couplings belongs to the same universality class as the two dimensional Ising model. 
B. Mirza, T. Mardani