Precise variational calculation of some S-states of Coulomb three-body systems with two identical particlesF. Arias de Saavedra, E. Buendía, F. J. Gálvez and A. SarsaEur. Phys. J. D, 2 2 (1998) 181-190DOI: https://doi.org/epjd/v2/p181(d7014)