APA

Nietzsche, . (1966). Thus spoke Zarathustra. New York: Penguin books.

Chicago

Nietzsche, . 1966. Thus spoke Zarathustra. New York: Penguin books.

Harvard

Nietzsche, . (1966). Thus spoke Zarathustra. New York: Penguin books.

MLA

Nietzsche, . Thus spoke Zarathustra. New York: Penguin books. 1966.