2nd order perturbation

A Most Probable Point Perturbation Method

abrupt perturbation

absolute and relative perturbation bounds

absolute perturbation

acoustic perturbation

Active Power Perturbation Analysis

additive gain perturbation

adiabatic perturbation

Algebraic perturbation

algebraic perturbation theory

amended perturbation solution

amplitude perturbation

amplitude-phase perturbation

analytic perturbation theory

approximate symmetry perturbation

artificial perturbation

astronomical perturbation technique

Asymmetrical perturbation

asymoptotic singular perturbation method