Best linear common divisors for approximate degree reduction. - Thomas W. Sederberg; Gengzhe Chang (Comput. Aided Des., 1993)

Nonnegative quadratic Bézier triangular patches. - Gengzhe Chang; Thomas W. Sederberg (Comput. Aided Geom. Des., 1994)

Over and over again. - Gengzhe Chang; Thomas W. Sederberg (Mathematical Association of America, 1997)