Foster, P. W. (1972). Programmed learning aid for introduction to environmental science. Learning Systems Company.
Chicago-Zitierstil (17. Ausg.)Foster, Phillips W. Programmed Learning Aid for Introduction to Environmental Science. Homewood, Illinois: Learning Systems Company, 1972.
MLA-Zitierstil (9. Ausg.)Foster, Phillips W. Programmed Learning Aid for Introduction to Environmental Science. Learning Systems Company, 1972.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.