Gaya APA
Riyanto, S.
(2013).
Gateway English For Active Communication
(
cet.7)
.
Yogyakarta:
Pustaka Pelajar.
Gaya MLA
Riyanto, Slamet.
"Gateway English For Active Communication".
cet.7
Yogyakarta:
Pustaka Pelajar,
2013.
Text.