Cita APA (7th ed.)
Tregidgo, P. S. (1979). English grammar in practice (ed.). Longman.
Cita Chicago (17th ed.)
Tregidgo, P. S. English Grammar in Practice. ed. England: Longman, 1979.
Cita MLA (9th ed.)
Tregidgo, P. S. English Grammar in Practice. ed. Longman, 1979.
Atenció: Aquestes cites poden no estar 100% correctes.