Simple determination of Na2 scattering lengths using observed bound levels at the ground state asymptoteA. Crubellier, O. Dulieu, F. Masnou-Seeuws, M. Elbs, H. Knöckel and E. TiemannEur. Phys. J. D, 6 2 (1999) 211-220DOI: https://doi.org/10.1007/s100530050303