Two-neutrino double- β decay of 94 ⩽ A ⩽ 110 nuclei for the 0+ → 0+ transitionR. Chandra, J. Singh, P. K. Rath, P. K. Raina and J. G. HirschEur. Phys. J. A, 23 2 (2005) 223-234DOI: https://doi.org/10.1140/epja/i2004-10087-7