THOMÉE, Vidar. Parabolic Difference Operators. MATHEMATICA SCANDINAVICA, [S. l.], v. 19, p. 77–107, 1966. DOI: 10.7146/math.scand.a-10797. Disponível em: https://tidsskrift.dk/math/article/view/10797. Acesso em: 14 aug. 2026.