APA-viite (7. p.)
English As a Second Language: A New Approach for the 21st Century : Student Leaflets Lessons 21-40. ModuLearn.
Chicago-viite (17. p.)
English As a Second Language: A New Approach for the 21st Century : Student Leaflets Lessons 21-40. California, EUA: ModuLearn.
MLA-viite (9. p.)
English As a Second Language: A New Approach for the 21st Century : Student Leaflets Lessons 21-40. ModuLearn.
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