Piero tredici Piper ringtone year 1976/77 6 -colored lithography Original signed in Lapis - Magnani paper Pescia full margin Tiratura: 99+x hc 70x50 cm References: catalog Il Bisonte 1983 n. 696 printer the bison Florence with a filigree logo Exemplary placed for sale: 46/99 (photo may refer to another number) perfect .