Citazione Stile APA (7a Edizione)

Rein, D. P., & Byrd, D. R. H. (1994). Spectrum: A communicative course in english: workbook. Prentice Hall Regents.

Citazione stile Chigago Style (17a edizione)

Rein, David P., e Donald R. H. Byrd. Spectrum: A Communicative Course in English: Workbook. New Jersey, EUA: Prentice Hall Regents, 1994.

Citatione MLA (9a ed.)

Rein, David P., e Donald R. H. Byrd. Spectrum: A Communicative Course in English: Workbook. Prentice Hall Regents, 1994.