Jonathan Mark Gilligan & Edward Eugene Eyler, Precise determinations of ionization potentials and $EF$ state energy levels of H$_2$, HD, and D$_2$, Physical Review A 46, 3676–3690 (1992). PDF Abstract:
Jonathan Mark Gilligan & Edward Eugene Eyler, Precise determinations of ionization potentials and $EF$ state energy levels of H$_2$, HD, and D$_2$, Physical Review A 46, 3676–3690 (1992). PDF