# Build the hash:
%HoL = (
           ASC=>["CRIS","ULEIS","SWIMS","EPAM","MAG","SIS",
		 "SEPICA","SWICS","SWEPAM","RTSW"],
           # more keys and their anonymous array values...
    );

# Ordinarily this would be a user prompted input:
$key="ASC";

# Look it up and print data:
print "$key instruments are:\n";
$array=$HoL{$key};
foreach $val (@$array) {
    print "$val \n";
}