P. Belli, R. Bernabei, R.S. Boiko, F. Cappella, F. Danevych, V. Tretyak: Search for alpha and double-alpha decays of naturally occurring europium isotopes with HPGe gamma spectrometry. Nuclear Physics A 1077, 123515 (2027). doi:10.1016/j.nuclphysa.2026.123515