Positron-impact direct ionization of lithium, sodium and potassium atoms R. Utamuratov, D. V. Fursa, A. S. Kadyrov, R. I. Campeanu, I. Bray and R. P. McEachran Eur. Phys. J. D, 75 10 (2021) 260 Published online: 30 September 2021 DOI: 10.1140/epjd/s10053-021-00256-8