B. Santosa, Nurhayati, and N. Hidayatullah, “Efficiency Analysis of Bank Buku 4 (Bank with Core Capital at Least Rp30 Trillion) Before and During The Covid-19 Pandemic: Efficiency Analysis of Bank Buku 4 (Bank with Core Capital at Least Rp30 Trillion) Before and During The Covid-19 Pandemic”, PENANOMICS, vol. 2, no. 3, Dec. 2023.