Authors
Stelian Ion
Institute of Statistical Mathematics and Applied Mathematics Romanian Academy Calea 13 Septembrie, No. 13,, Bucharest, Romania
Dorin Marinescu
Institute of Statistical Mathematics and Applied Mathematics Romanian Academy Calea 13 Septembrie, No. 13,, Bucharest, Romania
Stefan-Gicu Cruceanu
Institute of Statistical Mathematics and Applied Mathematics Romanian Academy Calea 13 Septembrie, No. 13,, Bucharest, Romania