  In this article we will be talking about Pickup and Delivery Problems with
Transfers (PDP-T), the main idea is to show first the Pickup and Delivery
Problem (PDP), which is the problem from which the PDP-T derives from, later
show a description of the problem and the mathematical formulation to get a
clear view of what we are going to solve, which leads us to present different
ways of solving this kind of problems.
