Searching for massive pre-stellar cores through observations of NH+ and ND+F. Fontani, P. Caselli, A. Crapsi, R. Cesaroni, S. Molinari, L. Testi and J. BrandA&A, 460 3 (2006) 709-720DOI: https://doi.org/10.1051/0004-6361:20066105
H+ and ND+H+ and ND+