| Three-level caching for efficient query processing in large Web search engines Recent countries visiting this post |  |
 | 7 | United States |
 | 3 | |
 | 1 | Sweden |
 | 1 | Japan |
| Three-level caching for efficient query processing in large Web search engines Recent countries visiting this post | |
| 7 | United States |
| 3 | |
| 1 | Sweden |
| 1 | Japan |