Marianne David on Twitter: "Is anyone looking for a Casio fx-991MS calculator? We've got one but it's the wrong one, school is asking for fx-991EX https://t.co/WqKmgmcnyh" / Twitter
Casio FX-991ES PLUS 2nd edition - Taschenrechner.ch
Im Fokus: Casio FX-991DE X - Das Buch zum Rechner und zum Erfolg - DynaTech