Cita APA (7a ed.)

Costinett, S., & Byrd, D. R. H. (1993). Spectrum 2A: A communicative course in english. Longman.

Cita Chicago Style (17a ed.)

Costinett, Sandra, y Donald R. H. Byrd. Spectrum 2A: A Communicative Course in English. White Plains: Longman, 1993.

Cita MLA (8a ed.)

Costinett, Sandra, y Donald R. H. Byrd. Spectrum 2A: A Communicative Course in English. Longman, 1993.