You may also wish to search for items by Vulpius.
Only one matching reference was found.
Houriet, R.; Vulpius, T., Formation of Metal Cluster Ions by Gas - Phase Ion - Molecule Reactions: the Bond Energies of Cr2+ and Mn2+, Chem. Phys. Lett., 1989, 154, 5, 454, https://doi.org/10.1016/0009-2614(89)87130-1 . [all data]