1. [1] A. Stancu,Centro-affine invariants for smooth convex bodies, arXiv: [math DG], (2010).
2. [2] E. De Angelis, T. Moons, L. Van Gool and P. Verstraelen,Complete systems of affine semi-differential invariants for plane and space curves, VIII. Proceedings of the international meeting on geometry of submanifolds, Brussels, Belgium, July 13–14, 1995 and Nordfjordeid, Norway, July 18– August 7, 1995. Singapore: World Scientific, (1996) 85–94.
3. [3] K. Aström,Affine invariants of planar sets, SCIA’93 Proceedings of the 8th Scandinavian Conference on Image AnalysisNOBIM-Norwegian Soc. Image Process. and Pattern Recognition, 2(1992).
4. [4] W. Barthel, Zur affinen Differentialgeometrie -Kurventheorie in der allgemeinen Affingeometrie, Proceedings of the Congress of Geometry, Thessaloniki(1987), 5–19.
5. [5] W. Blaschke, Affine Differentialgeometrie, Berlin, (1923).