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1. Visibility-Based Pursuit-Evasion in a Polygonal Region by a Searcher
   Sang-Min Park, Jae-Ha Lee, and Kyung-Yong Chwa
   In: Proceedings of the 28th International Colloquium on Automata, Languages and Programming (ICALP-01), Crete,Greece, July,8 - July,12, 2001, 456-468