Questions about the Measurement of the $\rm{e}^{+}\rm{e}^{-}$ Luminosity   Spectrum at a future linear Collider
  Important analyses at a future linear collider, including top-quark and W-boson mass measurements will depend upon the precise determination of the luminosity spectrum. This can be done, in principle,in the planned detectors. We review the problems to be solved, both beam-related and detector-related. 
Stewart T. Boogert and David J. Miller