  This paper presents a simple and systematic method to show how the potentials
in the Lorentz, Coulomb, Kirchhoff, velocity and temporal gauges yield the same
retarded electric and magnetic fields. The method appropriately uses the
dynamical equations for the scalar and vector potentials to obtain two wave
equations, whose retarded solutions lead to the electric and magnetic fields.
The advantage of this method is that it does not use explicit expressions for
the potentials in the above gauges, which are generally simple to obtain for
the scalar potential but generally difficult to calculate for the vector
potential. The spurious character of the term generated by the scalar potential
in the Coulomb, Kirchhoff and velocity gauges is noted. The non spurious
character of the term generated by the scalar potential in the Lorenz gauge is
emphasized.
