Rashed, H. Y., Imamura, J. N. 1996, Hydrodynamic Structures of Quasi-Periodic Oscillation (QPO) Sources , Mu'tah Journal for research and studies, Vol. 11, No. 6, 223.

Abstract: Short period optical quasi-periodic oscillations (QPOs) with 1%-3% root mean square (rms) amplitudes have been discovered in the white dwarf x-ray binary stars: V834 Cen, AN UMa, EF Eri, and in VV Pup.  It was proposed that QPOs were due to oscillatory instability of radiative shocks discovered by Langer, Chanmugam and Shaviv.  In this paper, we present only the results of our calculations of the time-dependent hydrodynamic structure of oscillating accretion shocks produced by flows onto magnetic white dwarfs.  Our results indicate that radiative shocks with parameters typical of AM Her QPO sources probably can not sustain limit cycle oscillations.