MELIN, Anders. A Remark on Invariant Pseudo-Differential Operators. MATHEMATICA SCANDINAVICA, [S. l.], v. 30, p. 290–296, 1972. DOI: 10.7146/math.scand.a-11085. Disponível em: https://tidsskrift.dk/math/article/view/11085. Acesso em: 14 aug. 2026.