STETKÆR, H. D’Alembert’s and Wilson’s functional equations for vector and $2\times 2$ matrix valued functions. MATHEMATICA SCANDINAVICA, [S. l.], v. 87, n. 1, p. 115–132, 2000. DOI: 10.7146/math.scand.a-14302. Disponível em: https://www.mscand.dk/article/view/14302. Acesso em: 24 apr. 2024.