1. Bourbaki, N.: Lie groups and Lie algebras, Chapters I, II-III, IV-VI, VII-VII. Masson 1971, 1972, 1981, 1998.
2. Dan-Cohen, E.: Borel subalgebras of root-reductive Lie algebras. J. Lie Theory 18(1), 215–241 (2008).
3. Dan-Cohen, E., Penkov, I.: Parabolic and Levi Subalgebras of Finitary Lie Algebras. Int. Math. Res. Not. IMRN 6, 1062–1101 (2010).
4. Dan-Cohen, E., Penkov, I., Snyder, N.: Cartan subalgebras of root-reductive Lie algebras. J. Algebra 308, 583–611 (2007).
5. Dimitrov, I., Penkov, I.: Borel subalgebras of
$$\mathfrak {gl}(\infty )$$
. Resenhas IME-USP 6, 111–119 (2004).