More non-semigroup Lie gradings

Elduque, 2006, A Lie grading which is not a semigroup grading, Linear Algebra Appl., 418, 312, 10.1016/j.laa.2006.02.006

Jacobson, 1962

Patera, 1989, On Lie gradings. I, Linear Algebra Appl., 112, 87, 10.1016/0024-3795(89)90591-0

M. Svobodová, Fine gradings of low-rank complex Lie algebras and of their real forms, SIGMA Symmetry Integrability Geom. Methods Appl. 4 (2008) 13 pp. (Paper 039).