APA

Spinoza B. d., . (1949). Ethics preceded by On the improvement of the understanding. New York: Hafner Pub. Co.

Chicago

Spinoza Benedictus de, . 1949. Ethics preceded by On the improvement of the understanding. New York: Hafner Pub. Co.

Harvard

Spinoza B. d., . (1949). Ethics preceded by On the improvement of the understanding. New York: Hafner Pub. Co.

MLA

Spinoza Benedictus de, . Ethics preceded by On the improvement of the understanding. New York: Hafner Pub. Co. 1949.