Gaya APA
Rangkuti-Hasibuan, S. (1986).
English for specific purposes : economics / Sofia Rangkuti-Hasibuan (Cet.3).
Jakarta:
Gramedia.
Gaya MLA
Rangkuti-Hasibuan, Sofia.
"English for specific purposes : economics / Sofia Rangkuti-Hasibuan".
Cet.3
Jakarta:
Gramedia,
1986.
Textbook.