1. refrence in this app.

2. Murray Bromberg and Julius Liebb,

(504 Absolutely Essential Words)

Sixth Edition

..............

3. Lynn Stafford-Yilmaz and Lawrence Zwier

(McGraw-Hill Education 400 Must-Have Words for the TOEFL)

2nd Edition

...................

4. Steven J. Matthiesen

(Essential Words for the TOEFL)

Seventh Edition

.................

5. Dr. Lin Lougheed

(Barron's Essential Words for the Ielts)

3nd Edition

...............

6. Anneli Williams

(Vocabulary for IELTS Collins)

...............

7. Lin Lougheed

(Barron's 600 Essential Words for the Toeic)

3nd Edition

.................

8. Philip Geer Ed.M.

(Essential Words for the GRE)

4nd Edition

....................

9. Murray Bromberg and Melvin Gordon

(1100 Words You Need to Know)

Seventh Edition

................

10. Paul Nation and Judy Schmauss

(4000 Essential English Words, Book 1)

2nd Edition

..........................

11. Paul Nation and Judy Schmauss

(4000 Essential English Words, Book 2)

2nd Edition

....................

12. Paul Nation and Judy Schmauss

(4000 Essential English Words, Book 3)

2nd Edition

......................

13. Paul Nation and Judy Schmauss

(4000 Essential English Words, Book 4)

2nd Edition

.....................

14. Paul Nation and Judy Schmauss

(4000 Essential English Words, Book 5)

2nd Edition

................

15. Paul Nation and Judy Schmauss

(4000 Essential English Words, Book 6)

2nd Edition

.......................

16. Casey Malarcher

(Illustrated Everyday Idioms with Stories, Book 1)

.......................

17. Casey Malarcher

(Illustrated Everyday Idioms with Stories, Book 2)

......................

18. Amy Gillett

(More Speak English Like an American)

Learn More Idioms & Expressions That Will Help You Speak Like a Native!

......................

19. Amy Gillett

(Speak English Around Town)

Conduct Everyday English Conversations with Confidence!

........................

20. Amy Gillett

(Speak Business English Like an American)

Learn the Idioms & Expressions you need succeed on the job!

................................

21. Amy Gillett

(Speak English Like an American)

............................

22. Murray Bromberg and Julius Liebb

(Barron's 601 Words You Need to Know to Pass Your Exam)

5th Edition

.....................

23. Linda Carnevale M.A.

(Hot Words for the SAT)

Seventh Edition

.........................

24. Kaplan Vocabulary

(500 flashcards feature the challenging college-level vocabulary)