Pearce, Joshua M.; Morris Blair, Christine; Laciak, Kristen J.; Andrews, Rob; Nosrat, Amir; Zelenika-Zovko, Ivana (2010). "3-D Printing of Open Source Appropriate Technologies for Self-Directed Sustainable Development". Journal of Sustainable Development. 3 (4). doi:10.5539/jsd.v3n4p17.