BLAŽIĆ, Novica; VUKMIROVIĆ, Srdjan. Examples of self-dual, Einstein metrics of $(2,2)$-signature. Mathematica Scandinavica, Berkeley, CA, United States, v. 94, n. 1, p. 63–74, 2004. DOI: 10.7146/math.scand.a-14430. Disponível em: https://journals.msp.org/mscand/article/view/789. Acesso em: 24 jul. 2026.