Gaya APA
Rangkuti-Hasibuan, S. (1992).
English for Specific Purposes : Tourism I Indonesian Socio-Cultural Life and Travel .
Jakarta:
Dian Rakyat.
Gaya MLA
Rangkuti-Hasibuan, Sofia.
"English for Specific Purposes : Tourism I Indonesian Socio-Cultural Life and Travel".
Jakarta:
Dian Rakyat,
1992.
BUKU.