Gaya APA
Nababan, P. et al
(1989).
An intermediate english course for student pilots
(
cet,1)
.
Jakarta:
Kesaint Blanc.
Gaya MLA
Nababan, P.W.J.. et al.
"An intermediate english course for student pilots".
cet,1
Jakarta:
Kesaint Blanc,
1989.
BUKU.