  Solutions of the general cubic complex Ginzburg-Landau equation comprising
multiple spiral waves are considered. For parameters close to the vortex limit,
and for a system of spiral waves with well-separated centres, laws of motion of
the centres are found which vary depending on the order of magnitude of the
separation of the centres. In particular, the direction of the interaction
changes from along the line of centres to perpendicular to the line of centres
as the separation increases, with the strength of the interaction algebraic at
small separations and exponentially small at large separations. The
corresponding asymptotic wavenumber and frequency are determined. These depend
on the positions of the centres of the spirals, and so evolve slowly as the
spirals move.
