Ruskin, R. S. (1974). The personalized system of instruction: An educational alternative. Americam Association for Higher Education.
Цитирование в стиле Чикаго (17-е изд.)Ruskin, Robert S. The Personalized System of Instruction: An Educational Alternative. Washington, D.C.: Americam Association for Higher Education, 1974.
Цитирование MLA (9-е изд.)Ruskin, Robert S. The Personalized System of Instruction: An Educational Alternative. Americam Association for Higher Education, 1974.
Предупреждение: эти цитированмия не могут быть всегда правильны на 100%.