Ruskin, R. S. (1974). The personalized system of instruction: An educational alternative. Americam Association for Higher Education.
芝加哥风格引文Ruskin, Robert S. The Personalized System of Instruction: An Educational Alternative. Washington, D.C.: Americam Association for Higher Education, 1974.
MLA引文Ruskin, Robert S. The Personalized System of Instruction: An Educational Alternative. Americam Association for Higher Education, 1974.
警告：这些引文格式不一定是100％准确.