Cita APA (7th ed.)

Costinett, S., & Byrd, D. R. H. (1993). Spectrum 2: A communicative course in English. Student book, 2A (1a. ed.). Regents.

Cita Chicago (17th ed.)

Costinett, Sandra, i Donald R. H. Byrd. Spectrum 2: A Communicative Course in English. Student Book, 2A. 1a. ed. Englewood Cliffs: Regents, 1993.

Cita MLA (9th ed.)

Costinett, Sandra, i Donald R. H. Byrd. Spectrum 2: A Communicative Course in English. Student Book, 2A. 1a. ed. Regents, 1993.