Operational dynamical modeling of spin 1/2 relativistic particles - The Dirac equation and its classical limitRenan Cabrera, Andre G. Campos, Herschel A. Rabitz and Denys I. BondarEur. Phys. J. Special Topics, 227 15-16 (2019) 2195-2207DOI: https://doi.org/10.1140/epjst/e2018-800075-7