Spencer, H. (1876). The principles of sociology: Vol. I. Williams and Norgate.
Chicago-Zitierstil (17. Ausg.)Spencer, Herbert. The Principles of Sociology: Vol. I. London: Williams and Norgate, 1876.
MLA-Zitierstil (8. Ausg.)Spencer, Herbert. The Principles of Sociology: Vol. I. Williams and Norgate, 1876.
警告：這些引文格式不一定是100％准確.