Hamisheh Bahar, Mahdi. “Beyond Propensity Score: The SAHR, Subgroup-Aware Holistic Ridge for Causal Inference in Observational Studies”. Research Annals of Industrial and Systems Engineering 3, no. 2 (June 9, 2026): 134–145. Accessed August 24, 2026. https://raise.reapress.com/journal/article/view/97.