Gaya APA
Costinett, S. et al (1987).
Spectrum 2 : a communication course in english (Cetakan kedua).
Unated states of America:
Prentice Hall.
Gaya MLA
Costinett, Sandra. et al.
"Spectrum 2 : a communication course in english".
Cetakan kedua
Unated states of America:
Prentice Hall,
1987.
Text.