On a tower of Ihara and its limit
Volume 151 / 2012
                    
                    
                        Acta Arithmetica 151 (2012), 191-200                    
                                        
                        MSC: Primary 11G20; Secondary 14H05, 14H25.                    
                                        
                        DOI: 10.4064/aa151-2-3