| Author | Popularity |
| Hillquit, Morris, 1870-1933 1870-1933 |
3 |
| Kautsky, Karl, 1854-1938 1854-1938 |
3 |
| Lafargue, Paul 1842-1911 |
3 |
| Lindemann, Hugo, 1867-1949 1867-1949 |
3 |
| Hillquit, Morris 1870-1933 |
2 |
| Hillquit, Morris |
1 |
| Hillquit, Morris Mitwirkender |
1 |
| Lindemann, Hugo |
1 |
| Lindemann, Hugo 1867-1949 |
1 |
| Müller-Wernberg, Karl |
1 |
