Unified subdivision generalizing 2- and 4-direction box splines. - Canjiang Ren; Guiqing Li; Weiyin Ma (CAD/Graphics, 2009)

Approximation of Loop Subdivision Surfaces for Fast Rendering. - Guiqing Li; Canjiang Ren; Jiahua Zhang; Weiyin Ma (IEEE Trans. Vis. Comput. Graph., 2011)