There are 4 mathematicians whose last name begin with KLEF.
| Klefenz, Frank | Ruprecht-Karls-Universität Heidelberg | 1992 |
| Kleffe, Jürgen | Humboldt-Universität zu Berlin | 1977 |
| Kleffe, Peter | Humboldt-Universität zu Berlin | 1976 |
| Klefsjö, Bengt | Umeå University | 1980 |