V. A. Zaytsev, Аndrey Volotka, D. Yu, S. Fritzsche, X. Ma, H. Hu, V. M. Shabaev, "Ab initio QED Treatment of the Two-Photon Annihilation of Positrons with Bound Electrons", Physical Review Letters, vol. 123, 2019, [DOI: 10.1103/physrevlett.123.093401] [IF: 8.39, SJR: 3.59]