Library  Download of the manual at http://www.usersmanualguide.com/  This machine is unique, it has 27 formulas usable for electronic studies.  These formulas are accessible using special keys located in the center of the keyboard. It's extremely rare to find such a specific key layout on a Casio scientific calculator.
Due to the particularity of this machine, it remains highly sought after by specialists.  It's a programmable calculator as well with 30-step capacity of storage