Two-photon sequential double ionization of argon in the region of Rydberg autoionizing states of Ar+Elena V. Gryzlova, Alexei N. Grum-Grzhimailo, Maksim D. Kiselev and Sergey M. BurkovEur. Phys. J. D, 73 5 (2019) 93DOI: https://doi.org/10.1140/epjd/e2019-90678-x