Gaya APA
Sikorzynska, M, H, D, M, A. (2002).
Opportunities: upper intermediate students' book .
England:
Pearson Education.
Gaya MLA
Sikorzynska, Michael, Harris;, David, Mowen;, Anna.
"Opportunities: upper intermediate students' book".
England:
Pearson Education,
2002.
Text.