8Alan F 1. Development of a Valve-Based Cell Printer for the Formation of Human Embryonic Stem Cell Spheroid Aggregates[J] . Biofabrication. 2013, (1): 1- 12.
9ohn E M. Carbide Formation. in a Nickel Based Super Alloy during Electron Beam Solid Freeform Fabrication[DJ. Massaehusetts , MIT, 1999.
10Karen M B T, Robert A H. Characterization of 2219 Aluminum Produced by Electron Beam Freeform Fabrication[CJ IIDavid L. Bourelleds The 13th Solid Freeform Fabrication Symposium. Austin: University of Texas At Austin, 2002: 482 - 489.