Cita APA (7a ed.)

Tregidgo, P. S. (1979). English grammar in practice. Longman.

Cita Chicago Style (17a ed.)

Tregidgo, P. S. English Grammar in Practice. Harlow: Longman, 1979.

Cita MLA (9a ed.)

Tregidgo, P. S. English Grammar in Practice. Longman, 1979.