Bikelis, A., and J. Mogyorödi. “On Asymptotic Expansion of the Convolution of N Multi-Dimensional Distribution Functions”. Lithuanian Mathematical Journal 10, no. 3 (September 15, 1970): 433–443. Accessed May 4, 2025. https://www.zurnalai.vu.lt/LMJ/article/view/20896.