Good article from 1987 explaining that the use of the term "dictatorship of the proletariat" in German by Marx and Engels is not the same as the English word "dictatorship" and does not conflict with democracy.
From workers autonomy to social autonomy: the experience of Socialisme ou Barbarie. An interview with Daniel Blanchard - Amador Fernández-Savater
Epub of Marx's Draft of an Article on Friedrich List’s book: Das Nationale System der Politischen Oekonomie. Text taken from marxists.org.