“…Here we can find some recent research on CAT(0) groups and their boundaries in [11], [13], [22], [27], [35], [36], [39], [41], [43], [44], [48] and [51]. Details of Coxeter groups and Coxeter systems are found in [6], [9] and [37], and details of Davis complexes which are CAT(0) spaces defined by Coxeter systems and their boundaries are found in [15], [16] and [47].…”