Gaya APA
Firsten, Richard, Strei, Gerry. (2007).
Contemporary english workbook 4 (2nd).
Boston:
McGraw-Hill.
Gaya Chicago
Firsten, Richard, Strei, Gerry.
Contemporary english workbook 4.
2nd
Boston:
McGraw-Hill,
2007.
Text.
Gaya MLA
Firsten, Richard, Strei, Gerry.
Contemporary english workbook 4.
2nd
Boston:
McGraw-Hill,
2007.
Text.
Gaya Turabian
Firsten, Richard, Strei, Gerry.
Contemporary english workbook 4.
2nd
Boston:
McGraw-Hill,
2007.
Print.