Hasibuan, Sofia
English for specific purposes : economics
Gramedia, 1986
Buku Teks
The handbook of English for specific purposes
Brian Paltridge, editor; Sue Starfield, editor
Wiley-Blackwell, 2013
Buku Teks
Rangkuti-Hasibuan, Sofia
English for specific purposes : medicine
Gramedia, 1986
Buku Teks
Community analysis in english for specific purposes (ESP)
Artikel Jurnal
Rangkuti-Hasibuan, Sofia
English for specific purposes : tourism. Indonesian socio-cultural life and travel
Dian Rakyat, 1992
Buku Teks