APA

Spears H., . (1950). Some principles of teaching. New York: Prentice Hall.

Chicago

Spears Harold, . 1950. Some principles of teaching. New York: Prentice Hall.

Harvard

Spears H., . (1950). Some principles of teaching. New York: Prentice Hall.

MLA

Spears Harold, . Some principles of teaching. New York: Prentice Hall. 1950.