Bibliographical references Falin, G. "A single-line system with secondary orders", Eng. Cybernet. Rev. 17 (2), (1978) 76-83. Falin, G. "Asymptotic propertles of the number of demands distribution in a M/G/1/oo., queueing system with repeated calls", Paper 5418-83, All-Union Institute for Scientific and Technical Information, Moscow, (1983). (in Russian). Falin, G. "Traffic measurements in M/G/1 retrial queues", preprint (1993). Kellson J., Cozzolino J. and Young H. "A service system with unfilled request repeated", Opero Res. 16, (1968) 1126-1137. Martin, M. and Falin, G. "Inference for M/M/1/., retrial queues", preprint (1994).