Ruskin, R. S. (1974). The personalized system of instruction: An educational alternative. Americam Association for Higher Education.
Chicago-Zitierstil (17. Ausg.)Ruskin, Robert S. The Personalized System of Instruction: An Educational Alternative. Washington, D.C.: Americam Association for Higher Education, 1974.
MLA-Zitierstil (9. Ausg.)Ruskin, Robert S. The Personalized System of Instruction: An Educational Alternative. Americam Association for Higher Education, 1974.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.