K. Havre and S. Skogestad, ``Selection of variables for regulatory control using pole vectors'', IFAC symposium DYCOPS-5, Corfu, Greece, 08-10 June 1998, 614-619.

Abstract.
This paper consider control structure design using the information given in the pole vectors. It is shown how the input and output pole vectors are related to the minimum input energy needed to stabilize a given unstable mode using one Single Input Single Output (SISO) control loop. The paper also look at stable but slow modes which need to be shifted further into the Left Half Plane (LHP) using feedback control. Moving stable slow modes are accomplished with pole placement and the results are interpreted in terms of Linear Quadratic Gaussian (LQG) control.