Comment on "From geodesics of the multipole solutions to the perturbed   Kepler problem"
  In this comment we explain the discrepancies mentioned by the authors between their results and ours about the influence of the gravitational quadrupole moment in the perturbative calculation of corrections to the precession of the periastron of quasielliptical Keplerian equatorial orbits around a point mass. The discrepancy appears to be consequence of two different calculations of the angular momentum of the orbits. 
L. Fern\'andez-Jambrina
gr-qc