Gaya APA
WALIDI, .
(2006).
STEP BY STEP TO SPEAK ENGLISH
.
Yogyakarta:
PT. CITRA AJI PARAMA.
Gaya MLA
WALIDI, .
"STEP BY STEP TO SPEAK ENGLISH".
Yogyakarta:
PT. CITRA AJI PARAMA,
2006.
Text.