Conrad, S., & Biber, D. (2001). Variation in English: Multi-dimensional studies. Longman.
Cita Chicago (17th ed.)Conrad, Susan, i Douglas Biber. Variation in English: Multi-dimensional Studies. Harlow, Eng: Longman, 2001.
Cita MLA (9th ed.)Conrad, Susan, i Douglas Biber. Variation in English: Multi-dimensional Studies. Longman, 2001.
Atenció: Aquestes cites poden no estar 100% correctes.