  We calculate the one-loop electroweak corrections to e+e- to WWZ and e+e- to
ZZZ and analyse their impacts on both the total cross section and some key
distributions. These processes are important for the measurements of the
quartic couplings of the massive gauge bosons which can be a window on the
mechanism of spontaneous symmetry breaking. We find that even after subtracting
the leading QED corrections, the electroweak corrections can still be large
especially as the energy increases. We compare and implement different methods
of dealing with potential instabilities in the routines pertaining to the loop
integrals. For the real corrections we apply a dipole subtraction formalism and
compare it to a phase-space slicing method.
