Some approximate equilibrium results for the E k / M / r no-queue system George P. Cosmetatos — 1977 RAIRO - Operations Research - Recherche Opérationnelle
An approximate analysis of the D/M/1 queue with deterministic customer impatience George P. Cosmetatos; Gregory P. Prastacos — 1985 RAIRO - Operations Research - Recherche Opérationnelle