Cita APA (7th ed.)

Seidl, J., & Swan, M. (1986). Basic english usage. Exercises. Oxford University Press.

Cita Chicago (17th ed.)

Seidl, Jennifer, i Michael Swan. Basic English Usage. Exercises. Oxford: Oxford University Press, 1986.

Cita MLA (9th ed.)

Seidl, Jennifer, i Michael Swan. Basic English Usage. Exercises. Oxford University Press, 1986.