Cita APA (7a ed.)

Allsop, J. (1988). Penguin english tests. Penguin Group.

Cita Chicago Style (17a ed.)

Allsop, Jake. Penguin English Tests. London [etc.]: Penguin Group, 1988.

Cita MLA (9a ed.)

Allsop, Jake. Penguin English Tests. Penguin Group, 1988.