Improved timing formula for the PSR B1257+12 planetary system
  We present a new analysis of the dynamics of the planetary system around the pulsar B1257+12. A semi-analytical theory of perturbation between terrestrial-mass planets B and C is developed and applied to improve multi-orbit timing formula for this object. We use numerical simulations of the pulse arrival times for PSR B1257+12 to demonstrate that our new timing model can serve as a toll to determine the masses of the two planets. 
Maciej Konacki (Torun Centre for Astronomy, Nicolaus Copernicus   University, Poland), Andrzej J. Maciejewski (Torun Centre ...