This section is included as an optional topic. It is intended for those who have experience in C or other languages which use pointers and references.
Readme: As mentioned earlier, references are covered in chapter 4 of the Camel. They are also covered at length in the first chapter of the O'Reilly book "Advanced Perl Programming" by Sriram Srinivasan (the "Panther" book). Lastly, perldoc perlref contains online documentation related to Perl references.
Uses for Perl references:
creating complex data structures, for example multi-dimensional arrays
passing multiple arrays and hashes to subroutines and functions without them getting smushed together
creating anonymous data structures