- CSB - MetaPress - Google - Bing - Yahoo
 | 2007 | |
|---|---|---|
| 1 |      | Jeremy Elson, John R. Douceur, Jon Howell, Jared Saul: Asirra: a CAPTCHA that exploits interest-aligned manual image categorization. ACM Conference on Computer and Communications Security 2007: 366-374 |
| 1 | John R. Douceur | [1] |
| 2 | Jeremy Elson | [1] |
| 3 | Jon Howell | [1] |