Gaya APA
DUFOUR, R., Strauss, J. (1978).
TANDEM: LANGUAGE IN ACTION SERIES .
Illinois:
INTERNATIONAL TEXTBOOK COMPANY.
Gaya MLA
DUFOUR, Richald.., Strauss, Jack..
"TANDEM: LANGUAGE IN ACTION SERIES".
Illinois:
INTERNATIONAL TEXTBOOK COMPANY,
1978.
Textbook.