BHATIA, A. K. Excitation of \((1s2s)\) \(^{1}S\), the Singlet State of Helium Atoms by Positron Impact. Journal of Atomic, Molecular, Condensed Matter and Nano Physics, [S. l.], v. 12, n. 1, p. 55–62, 2025. DOI: 10.26713/jamcnp.v12i1.3180. Disponível em: http://www.journals.rgnpublications.com/index.php/jamcnp/article/view/3180. Acesso em: 16 dec. 2025.