RAMM, Alexander G. Completeness of the set \(\{e^{ik\beta \cdot s}\}|_{\forall \beta \in S^2}\). Global Journal of Mathematical Analysis, [S. l.], v. 5, n. 2, p. 43–43, 2017. DOI: 10.14419/gjma.v5i2.7975. Disponível em: https://www.sciencepubco.com/index.php/GJMA/article/view/7975.. Acesso em: 29 apr. 2024.