Discriminating the minimal 3-3-1 models
  We show that due to the \rho parameter bound and the Landau pole limit, the reduced 3-3-1 model is unrealistic, while due to the \rho parameter and FCNCs bounds, the simple 3-3-1 model is experimentally unfavored. All such conditions strictly constrain the gauge symmetry breaking scales of the minimal 3-3-1 model with three scalar triplets. 
P. V. Dong, D. T. Si
hep-ph