1. L. Takács, “A single-server queue with feedback,” Bell System Technical J., Vol. 42, 505–519 (1963).
2. L. Takács, “A queuing model with feedback,” RAIRO — Operations Research — Recherche Opérationnelle, Vol. 11, No. 4, 345–354 (1977).
3. A. A. Nazarov, S. P. Moiseeva, and A. S. Morozova, “Analysis of retrial queueing systems with unlimited number of servers by the limiting decomposition method,” Vych. Tekhnologii, Vol. 13, Iss. 5, 88–92 (2008).
4. S. P. Moiseeva and I. A. Zakhorol’naya, “A mathematical model of parallel service of multiple retrial customers,” Avtometriya, Vol. 47, Issue 6, 51-58 (2011).
5. A. N. Dudin, A. V. Kazimirsky, V. I. Klimenok, L. Breuer, and U. Krieger, “The queueing model MAP | PH |1| N with feedback operating in a Markovian random environment,” Austrian J. of Statistics, Vol. 34, Iss. 2, 101–110 (2005).