1. Security-control methods for statistical databases;Adam;ACM Computing Surveys,1989
2. Make it fresh, make it quick — searching a networks of personal webservers;Bawa,2003
3. Space/time trade-offs in hash coding with allowable errors;Bloom;Communications of ACM,1970
4. Anatomy of a large-scale hyper-textual web search engine;Brin,1998
5. Private information retrieval;Chor,1995