Revisiting the Formation of HeH in the Planetary Nebula NGC 7027DOI: info:10.3847/1538-4357/ab9a50v. 89886
Forrey, R. C., Babb, James F., Courtney, E. D. S., McArdle, R. T., and Stancil, P. C. 2020. "Revisiting the Formation of HeH+ in the Planetary Nebula NGC 7027." The Astrophysical Journal, 898 86. https://doi.org/10.3847/1538-4357/ab9a50.