Nguyen, T. T., N. H. Pham, H. S. Tran, L. N. Cao, T. H. N. Pham, Q. B. Phan, and V. T. Tran. “Hydrogel 3D Printing With Direct and Indirect Extruder”. Mechanical Engineering Advances, Vol. 2, no. 2, Oct. 2024, p. 1470, doi:10.59400/mea.v2i2.1470.