Yu-Hung ChienZhe George ZhangXiaoling Yin2025-05-132025-05-132019-1110.1016/j.ejor.2019.03.042https://nutcir-lib.nutc.edu.tw/handle/123456789/316On optimal preventive-maintenance policy for generalized Polya process repairable products under free-repair warrantyjournal-article