O'Neill, R. (1979). American kernel lessons: Intermediate : tapescript for lab drills. Longman.
Citazione stile Chigago Style (17a edizione)O'Neill, Robert. American Kernel Lessons: Intermediate : Tapescript for Lab Drills. New York: Longman, 1979.
Citatione MLA (9a ed.)O'Neill, Robert. American Kernel Lessons: Intermediate : Tapescript for Lab Drills. Longman, 1979.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.