Murphy, R. Basic Grammar in use. Reference and practice for students of English (5a ed.).
Cita Chicago (17th ed.)Murphy, Raymond. Basic Grammar in Use. Reference and Practice for Students of English. 5a ed.
Cita MLA (8th ed.)Murphy, Raymond. Basic Grammar in Use. Reference and Practice for Students of English. 5a ed.
Atenció: Aquestes cites poden no estar 100% correctes.