CALDERBANK, D. M. J. The Faraday 2-form in Einstein-Weyl geometry. MATHEMATICA SCANDINAVICA, [S. l.], v. 89, n. 1, p. 97–116, 2001. DOI: 10.7146/math.scand.a-14332. Disponível em: https://www.mscand.dk/article/view/14332. Acesso em: 1 may. 2024.