Gaya APA
Humphreys, Pamela. (2013).
IELTS Express : Upper Intermediate Workbook (2nd Edition).
United Kingdom:
Cengage Learning.
Gaya Chicago
Humphreys, Pamela.
IELTS Express : Upper Intermediate Workbook.
2nd Edition
United Kingdom:
Cengage Learning,
2013.
Monograf.
Gaya MLA
Humphreys, Pamela.
IELTS Express : Upper Intermediate Workbook.
2nd Edition
United Kingdom:
Cengage Learning,
2013.
Monograf.
Gaya Turabian
Humphreys, Pamela.
IELTS Express : Upper Intermediate Workbook.
2nd Edition
United Kingdom:
Cengage Learning,
2013.
Monograf.