Cita APA (7th ed.)

TREGIDGO, P. Practical English usage for overseas: Students (2nd ed.). Longman.

Cita Chicago (17th ed.)

TREGIDGO, P.S. Practical English Usage for Overseas: Students. 2nd ed. London: Longman.

Cita MLA (9th ed.)

TREGIDGO, P.S. Practical English Usage for Overseas: Students. 2nd ed. Longman.