1. Proofs from The Book;Aigner,2001
2. Davenport-Schinzel sequences and their geometric applications;Agarwal,2000
3. Straight skeletons for general polygonal figures in the plane;Aichholzer,1998
4. A novel type of skeletons for polygons;Aichholzer;J. UCS,1995
5. Two-dimensional manifolds of bounded curvature. (Foundations of the intrinsic geometry of surfaces.);Aleksandrov,1962