Four-dimensional aether-like Lorentz-breaking QED revisited and problem of ambiguitiesA. P. Baeta Scarpelli, T. Mariz, J. R. Nascimento and A. Yu. PetrovEur. Phys. J. C, 73 8 (2013) 2526DOI: https://doi.org/10.1140/epjc/s10052-013-2526-3