1. The Art Gallery Theorem: Its Variations, Applications and Algorithmic Aspects;Aggarwal,1984
2. Covering regions with squares;Albertson;SIAM J. Algebraic Discrete Methods,1981
3. It's hard to color antirectangles;Boucher;SIAM J. Algebraic Discrete Methods,1984
4. Covering regions by rectangles;Chaiken;SIAM J. Algebraic Discrete Methods,1981
5. Decomposing a polygon into its convex parts;Chazelle,1979