MILLER, J.; STRANG, G. Matrix Theorems for Partial Differential and Difference Equations. MATHEMATICA SCANDINAVICA, [S. l.], v. 18, p. 113–133, 1966. DOI: 10.7146/math.scand.a-10786. Disponível em: https://www.mscand.dk/article/view/10786. Acesso em: 5 may. 2024.