  Two previous papers in this series have presented a study of the growth of
hadronic bubbles during the cosmological Quark--Hadron transition, treating the
material within each phase as a single perfect fluid. Here, we extend the
analysis to include the effects of long-range energy and momentum transfer by
weakly and electromagnetically interacting particles. After a short review of
the formalism adopted, we discuss the numerical strategies used in the computer
code which has been constructed in order to solve this system of equations.
Results for the growth of single hadronic bubbles are also presented.
