Complex transformation of the Kasner metric (Q1122801)

Although short, this paper gives a valuable survey of methods of relating two real solutions of Einstein's equations by complex transformations. It should be read in full. Also, as an example of the existence of more complicated transformations of this type, two members of the Kasner metrics [\textit{E. Kasner}, Am. J. Math. 43, 217-221 (1921)], i.e. the Bianchi I and the Weyl W-2, are shown to be related.