Dynamical phasing of Type II Cepheids
  In this paper we examine the problems of phasing using light curves and offer an alternate technique using the changes in acceleration to establish the zero point. We give astrophysical justification as to why this technique is useful and apply the technique to a selection of Type II Cepheids. We then examine some limitations of the technique which qualify its use. 
J. A. McSaveney, K. R. Pollard, P. L. Cottrell