LOU, R.(2011).WORKBOOK FOR ELEMENTARY - INTERMEDIATE LEARNERS OF ENGLISH AROUND THE WORLD: ENGLISH GRAMMAR AND HOW TO USE IT .Jakarta:MOBIL ENGLISH .
Gaya MLA
LOU, ROBBY."WORKBOOK FOR ELEMENTARY - INTERMEDIATE LEARNERS OF ENGLISH AROUND THE WORLD: ENGLISH GRAMMAR AND HOW TO USE IT".Jakarta:MOBIL ENGLISH ,2011.Buku Inti.