| 1 | Michael McCarthy, Felicity O'Dell, "English Vocabulary in Use", Cambridge University Press; 3rd edition, 2017 |
| 2 | Michael McCarthy, Felicity O'Dell,"English Phrasal Verbs in Use", Cambridge University Press; 2nd edition, 2017 |
| 3 | Raymond Murphy, "English Grammar in Use", Cambridge University Press; 5th edition, 2019 |