Fisher, D., & Day, J. (1963). Graded comprehension for advanced students.
Citazione stile Chigago Style (17a edizione)Fisher, David, e James Day. Graded Comprehension for Advanced Students. London, 1963.
Citatione MLA (9a ed.)Fisher, David, e James Day. Graded Comprehension for Advanced Students. 1963.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.