The Dialectic by Karl Kautsky
- Karl Kautsky's position on the place of Hegel's dialectic.
- http://www.marxists.org/archive/kautsky/1927/abstract/mch-abs.htm

Foundations of Christianity (1908)
- Online version of the seminal work by Karl Kautsky which explores the history of Christianity from a Marxist perspective.
- http://www.marxists.org/archive/kautsky/1908/christ/

Kautsky Internet Archive
- Document archive of Karl Kautsky. Includes "Marxism and Bolshevism," "The Class Struggle (Erfurt Program),"The Social Revolution," and other works by the German Marxist.
- http://www.marxists.org/archive/kautsky/index.htm