Gaya APA

ADAM, P, H, B, H, P. (1991). Socio-cultural issues in engglish for academic purposes . London: Makmillan Publishers Limited.

Gaya MLA

ADAM, Penny.,, HEATON,, Brian.,, HOWARTH,, Peter. "Socio-cultural issues in engglish for academic purposes". London: Makmillan Publishers Limited, 1991. BUKU.