van Tonder, Malan, Deon Johan de Beer, and Harry Wichers. “A QUALITY ASSURANCE FRAMEWORK FOR SULPHONIC ACID-COATED SAND USED IN 3D PRINTING APPLICATIONS”. The South African Journal of Industrial Engineering 31, no. 3 (November 11, 2020): 218–229. Accessed April 27, 2024. http://sajie.journals.ac.za/pub/article/view/2447.