Feng Lin Seah Hock Soon Yong Tsui Lee Deformable volumetric model and isosurface: exploring a new approach for surface boundary construction. 33-40 1996 20 Computers & Graphics 1 http://dx.doi.org/10.1016/0097-8493(95)00090-9 db/journals/cg/cg20.html#LinSL96