Heterodyne detection of phase-conjugate emission in an Ar discharge with a low-power c.w. laser D. Bloch, R.K. Raj, J.J. Snyder et M. DucloyJ. Physique Lett., 42 2 (1981) 31-34DOI: https://doi.org/10.1051/jphyslet:0198100420203100