Approximate Boolean operations on free-form solids. - Henning Biermann; Daniel Kristjansson; Denis Zorin (SIGGRAPH, 2001)

Evaluation of piecewise smooth subdivision surfaces. - Denis Zorin; Daniel Kristjansson (Vis. Comput., 2002)

Interactive modeling of topologically complex geometric detail. - Jianbo Peng; Daniel Kristjansson; Denis Zorin (ACM Trans. Graph., 2004)