The L A T E X 2ε source file of this paper was produced by converting a ChiWriter 3.16 source file into ChiWriter 4.0 file and then converting the latter file into a L A T E X 2.09 source file, which was manually edited for correcting numerous errors and for improving the appearance of the text. As a result of this procedure, some errors in the text may exist. Abstract A review of the parallel ...