在数学中,特殊线性群 SL₂(ℝ) 是行列式为 1 的 2×2 实矩阵组成的群: SL 2 ( R ) = { [ a b c d ] : a , b , c , d ∈ R {\displaystyle {\mbox{SL}}_{2}(\mathbb {R} )=\left\{{\begin{bmatrix}a
Review of Medical Physiology 24. 2012-04-05: 619. ISBN 978-0071780032. DeBoer SL. Emergency Newborn Care. Trafford Publishing. 4 November 2004: 30. ISBN 978-1-4120-3089-2