1. A game of cops and robbers;Aigner;Discrete Appl. Math.,1984
2. Searching and sweeping graphs: a brief survey;Alspach;Matematiche (Catania),2006
3. Maximum demand graphs for eternal security;Anderson;J. Comb. Math. Comb. Comput.,2007
4. The Game of Cops and Robbers on Graphs;Bonato,2011
5. Comparing complexity classes;Book;J. Comput. Syst. Sci.,1974