Cofer, C. N. (1972). Programmed learning aid for introduction to psychology. Learning systems co..
Chicago-viite (17. p.)Cofer, Charles N. Programmed Learning Aid for Introduction to Psychology. Illinois: Learning systems co., 1972.
MLA-viite (9. p.)Cofer, Charles N. Programmed Learning Aid for Introduction to Psychology. Learning systems co., 1972.
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