Rails call a class from a module

I have a rails 3.2 application where I use differents gem that I have created. I have a folder People and a folder Magazine, so in people I have a file

module Essa::Person
 class CarsDatatable < AjaxDatatablesRails::Base

I want to call CarsDatatable in a external module. How is the syntax to initialize CarsDatatable in a controller of the folder Magazione.

For example i try

CarsDatatable.new

or 

Essa::Person::CarsDatatable

but I have an error