Morris Marden, On the Zeros of Rational Functions Having Prescribed Poles, with Applications to the Derivative of an Entire Function of Finite Genre, Transactions of the American Mathematical Society, ...

The stability analysis of the transfer function consists in looking at the position these poles and zeros occupy in the s-plane.

Ushio Sumita, Yasushi Masuda, Classes of Probability Density Functions Having Laplace Transforms with Negative Zeros and Poles, Advances in Applied Probability, Vol. 19, No. 3 (Sep., 1987), pp.