(1970). Intensive course in English: Advanced 1. English Language Services, Inc.
Citazione stile Chigago Style (17a edizione)Intensive Course in English: Advanced 1. Washington, DC: English Language Services, Inc, 1970.
Citatione MLA (9a ed.)Intensive Course in English: Advanced 1. English Language Services, Inc, 1970.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.