As a reply to the Comment by I.S. Gorban {\it et al.} (Phys. Rev. B,
preceding paper) we summarize our criticism on their claim of the first
observation of the M series in β-ZnP2​. We support our analysis by
reporting the first observation of inverse {\it polariton} series from the
excitonic molecules selectively generated at Km​≃0 in a
CuCl single crystal. This observation and its explanation within the
bipolariton model complete our proof of the biexcitonic origin of the inverse
series.Comment: The Comment by I.S. Gorban et al. has been rejecte