Ram, Mangey, and S. B. Singh. 2012. “COST BENEFIT ANALYSIS OF A SYSTEM UNDER HEAD- OF-LINE REPAIR APPROACH USING GUMBEL- HOUGAARD FAMILY COPULA”. Journal of Reliability and Statistical Studies 5 (02):105-18. https://journals.riverpublishers.com/index.php/JRSS/article/view/21919.