Alexander Rand Noel Walkington Collars and Intestines: Practical Conforming Delaunay Refinement. 481-497 2009 IMR https://doi.org/10.1007/978-3-642-04319-2_28 http://imr.sandia.gov/papers/abstracts/Ra514.html conf/imr/2009 db/conf/imr/imr2009.html#RandW09