New possibility for further measurements of nucleon form factors at   large momentum transfer in time-like region: $\bar{p}+{p}\to \ell^+ +\ell^-$,   $\ell=e$ or $\mu$
  We briefly summarize the status with electromagnetic nucleon form factors, and give in this framework, arguments to study the angular dependence of the differential cross section and single-spin polarization phenomena (polarized target or polarized beam) in $\bar{p}+{p}\to \ell^++\ell^-$, in view of the availability of future antiproton beams. 
Egle Tomasi-Gustafsson and Michail P. Rekalo