A note on "Measuring propagation speed of Coulomb fields" by R. de   Sangro, G. Finocchiaro, P. Patteri, M. Piccolo, G. Pizzella
  In connection with the discussion and the measurements fulfilled in [R. de Sangro et al., Eur. Phys. J. C 75 (2015) 137], the full identity is demonstrated between the Feynman formula for the field of a moving charge and the Lienard-Wiechert potentials. 
D. M. Gitman, A. E. Shabad and A. A. Shishmarev
physics.class-ph hep-th