Muhammad Dzaky Al Tovic and Eko Budi Santoso (2026) “Frontier Shifts Without Ranking Changes: Evaluating Service Level Agreements on the Efficiency and Productivity of Energy Tanker Fleets Using a DEA–Malmquist Approach and Mixed Methods”, Jurnal Ilmiah Multidisiplin Indonesia (JIM-ID), 5(07), pp. 1953–1969. Available at: https://ejournal.seaninstitute.or.id/index.php/esaprom/article/view/8875 (Accessed: 17 August 2026).