| Verfasser | Häufigkeit |
| Jackson, Robert |
124 |
| Alexander, Robert Jackson 1918-2010 |
71 |
| Jackson, Robert H. 1892-1954 |
29 |
| Jackson, Robert H. 1938- |
27 |
| Jackson, Robert J. 1936- |
24 |
| Jackson, Robert H. |
17 |
| Jackson, Robert Louis 1923-2022 |
17 |
| Jackson, Samuel L. 1948- |
15 |
| Jackson, Robert G. |
13 |
| Jackson, Robert B. |
11 |
| Jackson, Doreen |
10 |
| Mathis, Robert L. |
10 |
| Jackson, John Harold 1945- |
9 |
| Jackson, Robert H. 1955- |
9 |
| Jackson, Robert 1945- |
8 |
| Sørensen, Georg 1948- |
8 |
| Bennett, Robert Jackson 1984- |
7 |
| Greville, Robert Kaye 1794-1866 |
6 |
| Hooker, William Jackson 1785-1865 |
6 |
| Jackson, James Robert de Jager |
6 |