Van, C. N., A. L. Hoang, C. D. Long, and D. N. Hoang. “Surface Roughness in Metal Material Extrusion 3D Printing: The Influence of Printing Orientation and the Development of a Predictive Model”. Engineering, Technology & Applied Science Research, vol. 13, no. 5, Oct. 2023, pp. 11672-6, doi:10.48084/etasr.6162.