A. Wongsoatmojo, F. A. D. Pratama, Ign. R. Haryosuprobo, A. A. Nugroho, B. W. B. Santoso, and Mardiatno, “Enhancing Bed Alignment and Reducing Calibration Time in 3D Printers Using Auto Leveling with PI Control”, j.rekayasa.mesin., vol. 21, no. 1, pp. 117–128, Apr. 2026.