Cita APA (7a ed.)

Seidl, J., & Swan, M. (1997). Basic English usage: Exercises. Oxford University.

Cita Chicago Style (17a ed.)

Seidl, Jennifer, y Michael Swan. Basic English Usage: Exercises. Oxford: Oxford University, 1997.

Cita MLA (9a ed.)

Seidl, Jennifer, y Michael Swan. Basic English Usage: Exercises. Oxford University, 1997.