Glass-Maujean, M. ; Schmoranzer, H ; Haar, I ; Knie, A ; Reiss, P ; Ehresmann, A: {The $J = 1$ para levels of the $v = 0$ to $6$ $np$ singlet Rydberg series of molecular hydrogen revisited}. In: J. Chem. Phys., 136 (2012), Nr. 13, S. 134301