Lie Groups Beyond an Introduction
《Lie Groups Beyond an Introduction》 · 第 325 页 · Chapter V，Section 7「Parabolic Subalgebras」，开头的对象约定及抛物子代数定义句（省略中间内容）
Let $\mathfrak g$ be a complex semisimple Lie algebra, and let $\mathfrak h$, $\Delta=\Delta(\mathfrak g,\mathfrak h)$, and $B$ be as in §2. […] Any subalgebra $\mathfrak q$ of $\mathfrak g$ containing a Borel subalgebra is called a parabolic subalgebra of $\mathfrak g$.