EL-Sherbeny, M. Salah, A. M. Rashad, and D. M. Gharieb. 2009. “THE OPTIMAL SYSTEM FOR SERIES SYSTEMS WITH WARM STANDBY COMPONENTS AND A REPAIRABLE SERVICE STATION”. Pakistan Journal of Statistics and Operation Research 5 (1), 1-17. https://doi.org/10.18187/pjsor.v5i1.150.