MLA

Cassirer, Ernst. The Problem of Knowledge: Philosophy, Science, and History Since Hegel. London: Yale University Press, 1950.

APA

Cassirer, E. (1950). The problem of knowledge: Philosophy, science, and history since Hegel. London: Yale University Press.

Chicago

Cassirer, Ernst The Problem of Knowledge: Philosophy, Science, and History Since Hegel. London: Yale University Press, 1950.