JESSEN, Borge. The Algebra of Polyhedra and the Dehn-Sydler Theorem. MATHEMATICA SCANDINAVICA, [S. l.], v. 22, p. 241–256, 1968. DOI: 10.7146/math.scand.a-10888. Disponível em: https://tidsskrift.dk/math/article/view/10888. Acesso em: 14 aug. 2026.