PortenkoN. I. (1966) “On integro-differential equations for distribution of probabilities of additive functionals of diffusion processes ”, Ukrains’kyi Matematychnyi Zhurnal, 18(5), pp. 60-68. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/8441 (Accessed: 27July2024).