Gaya APA
O'Driscoll, N., Barrett, F, S.
(2000).
Business Challenges Course Book
.
Essex Engand,:
Pearson Education.
Gaya MLA
O'Driscoll, Nina., Barrett, Fiona, Scott.
"Business Challenges Course Book".
Essex Engand,:
Pearson Education,
2000.
UMUM.