ALBEVERIO, S. A. .; AYUPOV, S. A. .; OMIROV, B. A. . Root Arrangements of Hyperbolic Criterion of Solvability of Finite Dimensional Leibniz Algebras. Revista Matemática Complutense, v. 19, n. 1, p. 197–225, 27 Abr.2006 https://doi.org/10.5209/rev_REMA.2006.v19.n1.16654.