Caraffini, G. L., and D. Ya. Petrina. “Analog of the Liouville Equation and BBGKY Hierarchy for a System of Hard Spheres With Inelastic Collisions”. Ukrains’kyi Matematychnyi Zhurnal, vol. 57, no. 6, June 2005, pp. 818–839, https://umj.imath.kiev.ua/index.php/umj/article/view/3646.