Classification of surfaces in ℝ 3 which are centroaffine-minimal and equiaffine-minimal. Liu, Huili — 1996 Bulletin of the Belgian Mathematical Society - Simon Stevin
Centroaffine surfaces with parallel traceless cubic form. Liu, Huili; Wang, Changping — 1997 Bulletin of the Belgian Mathematical Society - Simon Stevin
Centroaffinely homogeneous surfaces in ℝ 3 . Liu, Huili; Wang, Changping — 1994 Beiträge zur Algebra und Geometrie