Gaya APA
Riyanto, S.
(2004).
Gateway English For Active Communication
(
Cet. 1)
.
Yogyakarta:
Pustaka Pelajar.
Gaya MLA
Riyanto, Slamet.
"Gateway English For Active Communication".
Cet. 1
Yogyakarta:
Pustaka Pelajar,
2004.
Text.