Illinois. University. Elementary School Science Project. (1966). Astronomy: Gravitation; teacher's guide 3 (4th ed.). University of Illinois.
Цитирование в стиле Чикаго (17-е изд.)Illinois. University. Elementary School Science Project. Astronomy: Gravitation; Teacher's Guide 3. 4th ed. Urbana: University of Illinois, 1966.
Цитирование MLA (9-е изд.)Illinois. University. Elementary School Science Project. Astronomy: Gravitation; Teacher's Guide 3. 4th ed. University of Illinois, 1966.
Предупреждение: эти цитированмия не могут быть всегда правильны на 100%.