1. Myshkis, A.D. and Filimonov, A.M., Nepreryvnye resheniya
giperbolicheskikh sistem kvazilineinykh uravnenii s dvumya nezavisimymi peremennymi. Nelineinyi
analiz i nelineinye differentsial’nye uravneniya (Continuous Solutions of Hyperbolic
Systems of Quasilinear Equations with Two Independent Variables. Nonlinear Analysis and
Nonlinear Differential Equations), Moscow: Fizmatlit, 2003.
2. Petrovskii, I.G., Lektsii po teorii obyknovennykh differentsial’nykh
uravnenii (Lectures on the Theory of Ordinary Differential Equations), Moscow: Izd.
Mosk. Gos. Univ., 1984.
3. Rozhdestvenskii, B.L. and Yanenko, N.N., Sistemy kvazilineinykh
uravnenii (Systems of Quasilinear Equations), Moscow:
Nauka, 1978.
4. Chakravarthy, S.R., Krishnamoorthy, A., and Ushakumari, P.V., A (
$$k
$$-out-of-$$n
$$) reliability system with an unreliable server and
phase type repairs and services: The $$(N,T)$$ policy,
J. Appl. Math. Stochastic Anal., 2001, vol. 14(4),
pp. 361–380.
5. Cox, D.R., The analysis of non-Markovian stochastic processes by the
inclusion of supplementary variables, Math. Proc. Cambridge Philos.
Soc., 1955, vol. 51(3), pp. 433–441. https://doi.org/10.1017/S0305004100030437