Fauziah Amarani, Sugianto and Muhammad Lathief Ilhamy Nasution 2024. The Effect of Self-Efficacy and Self-Concept on Increasing Optimism in Achieving Targets in Employees of Bank Syariah Indonesia (BSI) Case Study of BSI KCP Medan Aksara . Jurnal Manajemen Bisnis. 11, 2 (Aug. 2024), 985–998. DOI:https://doi.org/10.33096/jmb.v11i2.893.