New Use of a Three-Dimensional Pellet Culture System for Human Intervertebral Disc Cells: lnitial Characterization and Potential Use for Tissue Engineering. - Lee,J.Y.; Hall,R.; Pelinkovic,D.; Cassinelli,Z.; Usas,A.; Gilbertson,L.; Huard,J.; Kang,J. (Spine, 2001)