Merker, Joël, and Paweł Nurowski. “Five-Dimensional Para-CR Manifolds and Contact Projective Geometry in Dimension Three”. ANNALI SCUOLA NORMALE SUPERIORE - CLASSE DI SCIENZE 24, no. 1 (December 27, 2021): 519-549. Accessed June 14, 2025. http://20.103.181.36/index.php/annaliscienze/article/view/5745.