(1)
Bassi, J. On $C^*$-Algebras Associated to Actions of Discrete Subgroups of $\operatorname{SL}(2,\mathbb{R})$ on the Punctured Plane. Math. Scand. 2020, 126 (3), 540-558. https://doi.org/10.7146/math.scand.a-120288.