Halverscheid, Stefan, and Andrea Iannuzzi. “On Naturally Reductive Left-Invariant Metrics of SL (2, R)”. ANNALI SCUOLA NORMALE SUPERIORE - CLASSE DI SCIENZE 5, no. 2 (December 4, 2009): 171-187. Accessed February 20, 2026. https://journals.sns.it/index.php/annaliscienze/article/view/96.