Gaya APA
Costinett, S., Byrd, D, R, H. (1993).
Spectrum 2, a communicative course in English .
White Plaints, NY.:
Prentice-Hall.
Gaya MLA
Costinett, Sandra., Byrd, Donald, R., H..
"Spectrum 2, a communicative course in English".
White Plaints, NY.:
Prentice-Hall,
1993.
Text.