Cita APA (7th ed.)

Spencer, H. (1891). The Principles of Ethics (2nd thousand.). Williams and Norgate.

Cita Chicago (17th ed.)

Spencer, Herbert. The Principles of Ethics. 2nd thousand. London ; Edinburgh: Williams and Norgate, 1891.

Cita MLA (8th ed.)

Spencer, Herbert. The Principles of Ethics. 2nd thousand. Williams and Norgate, 1891.