“…Maybe the simplest of these is the mixed spin-1/2 and spin-1 Ising system and has been studied with many techniques including the renormalization-group technique [2], high-temperature series expansions [3], the free-fermion approximation [4], the recursion method on the Bethe lattice [5], the Bethe-Peierls approximation [6], the framework of the effectivefield theory [7,8], the mean-field approximation [9,10], the finite cluster approximation [11], the Monte-Carlo simulation [12,13], the mean-field renormalization-group technique [14], a numerical transfer matrix study [13] and the cluster variation method in pair-approximation [15]. The next possibility, including spin-1/2, is the mixed spin-1/2 and spin-3/2 Ising systems and includes the works with the transverse Ising model with a crystal field within the framework of the effective-field theory with correlations on the honeycomb lattice [16], on a square lattice by using the effective-field theory [17,18], again on a square lattice with a Monte Carlo algorithm [19] and on the Bethe lattice by using exact recursion relations [20]. Of course, the next possible mixing with spin-1/2 is with spin-2.…”