LANDSTAD, Magnus B. Algebras of spherical functions associated with covariant systems over a compact group. Mathematica Scandinavica, Berkeley, CA, United States, v. 47, p. 137–149, 1980. DOI: 10.7146/math.scand.a-11880. Disponível em: https://journals.msp.org/mscand/article/view/1768. Acesso em: 25 jul. 2026.