Gaya APA
Kon, T.
(1991).
Practical English Usage 4 : English as a second Language / T.S Kon
.
Jakarta:
Bina Aksara.
Gaya MLA
Kon, T.S.
"Practical English Usage 4 : English as a second Language / T.S Kon".
Jakarta:
Bina Aksara,
1991.
Buku.